The Hydro Station is the remains of a large redistribution facility that supplies fresh water to other regions of the planet. The station itself is composed of several chambers, some of which are connected via pipes and tunnels used to shuttle water to different locations. Powerful items can be found in the deepest pockets, including the Varia Suit which significantly reduces the amount of damage Samus receives from attacks. Some items are well hidden and difficult to reach, while others must be pried from the hands of the aggressive creatures which defend them. A total of seven Metroid must be defeated, including the first who reach a new, more deadly phase of evolution.
Reaching the station
After defeating the Ancient Guardian, exit the room to the left. Drop down to the bottom of room A, and run left back to room B. Due to the earthquake, the lava which once floated near the surface of room B has receded, allowing you to explore further below ground. You'll need a bomb to blast through the hardened rock that blocks you from dropping into the lower passage.
After dropping down and running to the right a bit, you must drop down again. You may notice a narrow passage exiting to the right. If you bomb the rock in the way, you can gain access to the passage, but inside room C you'll find it difficult to climb to the top in your current state. You'll need to return here with more power if you wish to investigate the top. There is, however, one item you can grab now. See the section below.
Continue to follow the passage through room B as it zig zags back and forth. Eventually you will reach what appears to be the bottom, although you will notice a narrow passage below the ground. Head right into room D. On the far right side, you may notice another narrow passage into a room on the right. However, that room is even less forgiving than room C above, and there's nothing you can obtain from it at this time.
The lava along the bottom of room D prevents you from going any further below, but there are enough rocks to use as platforms and travel back to the left. Return to room B through that narrow passage below the ground. Keep going left until you reach the entrance to room E. As you run to the left through the next room, you will notice a rocky outcropping. When you get close to it, an Alpha Metroid will burst from the rock and attack you. Defeat it just as you have with the previous Alphas, and then enter the Hydro Station through the door on the left.
- Missile Tank A (room C)
- While you may be distracted trying to figure out a way to reach higher ground in this room, the Missile Tank is hiding low in the ground on the right. Use Bombs to access it.
Investigating the station
Before you attempt to take out the remaining Metroids in this area, and trigger the next earthquake, there are several opportunities to boost Samus' power, both offensively and defensively. You can accomplish these in any order you wish. The order below is just one example.
- Obtaining the Varia Suit (A → F)
Like room C of the Golden Temple, room A that you arrive in is actually a large cavern surrounding the Hydro Station. Many doors lead to and from this area. For now, head to the left across the bridge and enter through the door. You'll arrive in a room with what appears to be a busted save station. Continue left into room B. As you run to the left, after being forced to use the Morph Ball to squeeze through a narrow passage, you will encounter a set of three security robots. Due to the way they're positioned, it takes a little work to kneel down and defeat them, so you might be better off just leaping over them and the lasers they fire. To room to the left beyond room B features a functioning save station.
Beyond the save station to the left, you have a couple of options. You could try to climb up the wall above you, attempt to traverse the broken bridge to the left, or drop down into the water. If you want to increase Samus' defense first, drop down into the water. Samus' movement is significantly hampered by the water, so be prepared to move quite a bit slowly. If you investigate the right side under water, below the save station, you will see what looks like a door with a large machine blocking the way. You can remove the machine with three missiles, or a number of Bombs. When you do, some of the water will drain into the passage, and the water level will decrease. Head right into room C.
In room C, you will see a turbines in the floor which suck water into them. As Samus gets closer to them, she will also start to get sucked in. The turbines don't do a lot of damage, but you will need to remove them in order to proceed. Missiles or Bombs can remove them. As you destroy each one, the water level will drain further down until you can access the floor. Head right into room D.
You can slowly wade through the waist-high water as you head to the right, or you can move slightly faster by rolling in Morph Ball form. Continue to the end where an Alpha Metroid will be waiting to attack. Destroy it before attempting to explore the rest of the room. With the Metroid cleared away, jump up to the large machine above the floor. This is a water compressor that will spray water at a very high pressure. If you shrink down into a Morph Ball while standing on the center, the machine will activate, and send you blasting through an upward pipe. You will climb three levels and arrive in room E.
Climb up out of the small chamber, through the pipe between the wall. Watch out for the enemies in the room and head to the door on the left. You will arrive in room F, with what appears to be an inert Chozo statue. Interacting with the statue does nothing. But if you bomb around the room, particularly behind the statue, you will discover a hidden passage to the room behind the statue. Roll into the small back room to find a large number of rocks. Bomb your way to the rock in the center of the floor, and shoot it to discover the Varia Suit. Collect this suit to reduce the amount of damage that Samus takes by 50%, effectively doubling her energy.
After grabbing the suit, return the way you came to get back to room C, where you destroyed the turbines.
- Obtaining the Wave Beam (C → H)
Climb to the top of room C, and return to the portion of room A that used to be underwater. To return to the save station above, you can climb up using some debris from the destroyed bridge. Save your game, and return to room A through the left door. Begin power-gripping your way up the left side of the hydro station until you reach the first roof level. Run to the right, and turn into a Morph Ball to access the door to room G.
Run through the corridor to reach an open area, where you'll encounter another Alpha Metroid. Destroy it, and bomb the cracked brick in the lower right corner. Navigate up the pipes until you reach a small chamber. You'll see a Missile Tank in the upper right corner, but you can't access it from this direction. Turn into a Morph Ball and drop down the drain in the floor of the chamber. Navigate the pipe to continue dropping several levels below.
You'll land on top of a water compressor in room H. A bouncing mechanical robot will be guarding the area. They take quite a few shots to destroy, so you may wish to consider using missiles if you have plenty. When you land, it appears as though you can only go to the right, but the map indicates that you can actually proceed to the left. If you bomb the floor you'll find a small narrow passage, but you can't actually proceed to the left through it. The actual access is higher off the floor. Use Spider Ball to climb up to and bomb the cracked brick in the wall.
Once you succeed in accessing the room to the left, you will see two large mechanisms that look like centrifuges. You can bomb your way into the right one, and begin spinning around inside. You must time the release of another bomb so that you destroy the blocks above, and gain access to the upper passage. Head left and you will drop into the left spinner. Once again, time the release of a bomb so that you destroy the left wall and escape.
Shoot the security statue, and bomb the wall above it to access the red door beyond. Shoot the door with a missile and step inside. You'll find a Chozo statue with an orb containing the Wave Beam. Now you will be able to shoot your weapon through walls to attack enemies beyond your reach.
- Obtaining the Hi-Jump Boots (H → J)
Return from the Chozo statue to the right. Rather than passing through the centrifuges, you can take a one-way shortcut through a passage closer to the floor. Watch out for the bouncing robots, and proceed to the right, bombing another wall to reach the door that leads to room I.
Although it's easier to fall straight down to the bottom of room I, it's better to descend carefully and access the door in the middle of the room on the right side. Pass though the door to room J. Do drop to the very bottom of room J, and shoot the red door open with a missile. Step inside, and you'll find another Chozo statue with an orb. This time, it contains the Hi-Jump Boots.
At this time, there are no more core items to obtain in this portion of the Hydro Station. There is one more power-up to locate near the top. However, there are quite a few Missile Tanks, and even an Energy Tank to locate in this area, and you can start by thoroughly investigating the Chozo statue room.
- Obtaining the Spring Ball (I → N)
After collecting the Hi-Jump Boots, you must jump your way up room J (which is now possible thanks to the boots) and back up to the top of room I. You can reach the top of room I through several means, including blasting holes through the pipes or wall jumping back and forth between them. Exit left to room H and return to the water compressor. Use the Morph Ball to get blasted back up to room G, and step outside to the left to return to cavernous room A.
With the Hi-Jump Boots, you should have no problem continuing to climb up the left side of the station. Reach the second roof level. Make note of the floating remains of a bridge off to the left, you'll need to return there shortly. Run to the right for now and you will eventually encounter a hole in the roof top. Drop down to room N below and you'll find a save station. Save your game, and then drop to the floor.
Bomb your way through the pipes to the lower left of the save station. Once inside, you must shoot and bomb your way through the rest of the pipes until you reach the red door on the left. Blast it open with a Missile and step inside. Once in, the door will lock shut behind you. You'll see what looks like a Chozo statue with no orb. Approach it, and it will begin to shake and crumble, revealing the creature known as Arachnus.
You must now defeat this creature in order to escape. It will leap into the air, spin into a ball, and crash down to the floor in your direction. Then it will stay on the floor and engage you with one of several different kinds of attacks. It make slash the air with its claws, or it may spit a fireball at you. Regardless, begin pelting it with missiles if you have any, or shoot it with your regular gun. You attacks will only work for so long before they begin to bounce off of Arachnus. At that time, it will roll into a ball and try to crush you. To stop it, you need to use the Morph Ball and lay bombs along the floor. When Arachnus rolls over them, they will automatically detonate, and pop him into the air. The more bombs he detonate, the higher he will fly, until he is ultimate impaled against one of the electrical nodes on either wall. After getting shocked, he will resume his attack and become vulnerable to your weapons again. This pattern will repeat itself until he is shocked the third time. When this happens, he will be destroyed, and he will leave one of the Chozo artifacts behind: the Spring Ball. With this item, you will possess the ability to jump in Morph Ball form. You can use the Spring Ball to help you access a faster method across room N along the top.
- A lone Metroid (N → O)
Climb up through the ceiling of room N to return to room A, and run to the left. When you reach the end of the roof, you should see the partial remains of a bridge out to the left. Hop over to them, and use each piece as a platform to get to the left. You will reach the entrance to a chamber with a shed Metroid skin sitting outside.
Step inside to access room O, and run to the left end of the room. You will encounter another Alpha Metroid. If you have been following along in this walkthrough, you will have just three Metroid remaining in this area after defeating the one in room O.
- Clearing the nest (O → S)
From room O, head back to the right to return to cavernous room A. Drop down to return to the broken bridge above the area where the water used to be. Cross the broken bridge to reach the entrance to room P. There is a locked door across the room, and a strange mechanism at the bottom, which will remain a mystery for now. However, from the strange mechanism, you can jump up and reach the ledge above the spike-lined walls, provided you collected the Hi-Jump Boots. Leap to this ledge and proceed to the left to find a save station.
Save your game and continue left to reach room Q. The music will shift to a slower, darker take on the same theme. Begin dropping down to the bottom, shooting out the blocks that get in your way. Below those blocks is an entrance on the right that leads to room R. Step inside, and make your way through this large room to the right until you find the Alpha Metroid waiting inside. Destroy it, doing your best to remain safely on a ledge, and not get pushed down into the thorns below. Then return to the left to room Q.
Continue dropping to the bottom and enter the passage on the left to room S. Run to the left and you will see an entrance to another chamber across the way. (There is an item to discover if you look around. See the Item Gathering section below.) Jump over to access room T. Head to the far left to do battle with another Alpha Metroid. Then return to the right to room S, and begin dropping to the bottom. You'll need to bomb or shoot the bricks in the middle of the passage. The bricks further below are brittle and will begin to decay when you step on them. Continue right to reach the lowest portion of the nest towards room U.
You will pass through what appears to be an empty tunnel with two pipes. Continue to room U to fight another Alpha Metroid. It would seem as though you destroyed all of the remaining Metroids, but the earthquake hasn't been triggered. Run back to the tunnel to the left of room U. As you cross the room, you will stumble across another Alpha Metroid. However, this is no ordinary Alpha Metroid. It is on the verge of spontaneously evolving into a Gamma Metroid. It will metamorph before your eyes, becoming bigger and more aggressive.
The strategy of a battle with a Gamma Metroid remain basically the same as with an Alpha Metroid: you want to position yourself to have the greatest opportunity to shoot the exposed green under-belly of the creature. However, the mechanics are different because a Gamma Metroid is better protected and more dangerous. In addition to the greater amount of armor they have covering their body, they have a few new attacks including an electrical attack that they can launch. They also possess the ability to rush you and pick you up off the ground if caught. This attack can do a tremendous amount of damage to Samus, and should be avoided at all costs. If you see a Gamma Metroid rear back, you know it is preparing to rush over and grab you, so seek some safety. Do everything you can to fire as many Missiles into the under-belly as quickly as possible to reduce the threat of this dangerous predator.
With this final Metroid defeated, you will finally experience the next earthquake (assuming you followed along with the guide and destroyed all the others.) From here there is nothing left to do but to return to room A, and head back out through the right side to where the lava once previously prevented you from going lower. There are no surprise boss battles this time.
- Missile Tank A (room A)
- At any time, you can Spider Ball up the right side of the cavern wall above the entrance to the Hydro Station, and navigate the wall until you collect the Missile Tank waiting for you on the ledge.
- Missile Tank B (room C)
- On the right side of the top of the room, there is one brick which you can bomb to reveal a passage into the ceiling, where the Missile Tank can be found.
- Missile Tank C (room D)
- The tank is visible in the upper left corner of the room. Figuring out how to reach it isn't as obvious. The easiest way to access it is to connect to the left portion of the ceiling above the water compressor, and make your way left across the ceiling until you begin to access a hidden passage in the ceiling. Continue rolling all the way to the left to collect the tank.
- Missile Tank D (room E)
- You can see this tank when you're blasting through certain pipes, but accessing it takes some work. To reach it, you must be in room E, on the way to the Varia Suit. In this room, there is a brick in the upper right corner of the main room which can be bombed. Once open, you can access a small hidden pipe that connects to the right side of room E. From here, you must bomb your way into a series of pipes which circulate water around. Keep bombing until you can access the bottom portion of the pipe. Dropping in as a Morph Ball will get you swept up in the current and send you around in a loop. Once you return to the top, you can bomb to regain access to the pipe below. Along the trip, you get close to the tank, but to access it, you must drop a bomb at the correct time to blast the wall open. After setting the bomb correctly, you can enter the pipe again, and hold left to make your way out of the current and collect the tank. Then reenter the current and make your way back to the left.
- Missile Tank E (room K)
- Drop to the bottom of room I and enter room K through the door on the left. When you enter the room, bomb the lower right corner of the room to discover a hidden passage below the floor. Enter this passage and travel all the way to the left until you are forced to stop below the tank. Bomb the floor above you to create an opening and collect the tank.
- Missile Tank F (room K)
- This tank is in a small chamber below the ceiling in the same room as Missile Tank F. To collect it, you must use the Spider Ball to bomb the pipes along the left side of this small chamber. It is easier to do this if you first clear out the bouncing robot. It is even easier if you collected the Hi-Jump Boots first. If the bomb blast knocks you off the ceiling, you can simply jump back up and Power Grip your way into the chamber.
- Missile Tank G (room M)
- From room K, head through the door on the left to room L and drop to the bottom. Access room M through the door on the right and you'll see another Missile Tank in a small chamber. Given how complicated some of the previous Missile Tanks were, this one is relatively simple. Bomb the left side of the chamber to create an opening and enter to collect the tank. If you did not yet collect the Hi-Jump Boots, you will likely see Missile Tank H and Energy Tank A on the other side of the wall, and you will not be able to access either of them from this direction.
- Missile Tank H (room M)
- You'll see this Missile Tank directly above Energy Tank A. Read that entry below to learn how to access this room. After you collect the Energy Tank, Spider Ball up to the ceiling, and bomb the pipe to the right of the Missile Tank to create an opening for you to enter and collect the tank.
- Missile Tank I (room G)
- You may have seen this tank from the left side on your way to collect the Hi-Jump Boots, but the way to reach it is actually from the outside of the station in room A. Run to the right of the hole in the roof that leads to the Spring Ball, and fall down as a Morph Ball. Hug the right wall, and you should reach a spot along the wall where you can take a small passage into the room beyond to collect the tank. Alternatively, you can use the Spider Ball to climb up and reach it from the ground below.
- Energy Tank A (room M)
- To get this Energy Tank, you must access room M through the right side, where the Hi-Jump Boots were found. Bomb the platform to the right of the statue, and then bomb the lower left corner of the room to discover a narrow passage to the left. Travel through the passage to find this Energy Tank, as well as Missile Tank H.
- Energy Tank B (room S)
- When you first enter this room from room Q, run to the left but stop before the first drop. The block in front of the thorns is actually in the background, and you can run right through it. Brave the thorns and when you reach the right wall, bomb the wall just below the floor above to expose an Energy Tank. Collect it before doing battle with the Metroids in the nest.
In all likelihood, you are making your return visit here by arriving through the Transportation chute in The Tower. You arrive in room V, and you can make your way out through either side by using the Screw Attack to break through the walls.
- Super Missiles A (room W)
- If you already activated the Distribution Center, return to room P. There will be a Power Cell waiting at the very top of it. Use bombs to knock it down to the very bottom where a structure awaits. Guide the cell into the structure to activate the door to room W above. When you enter room W, you need to build up speed as you run to the left so that you clear the dissuolving bridges, and can Shinespark through the barrier that blocks the Super Missile tank on the far left. You can use Super Missiles to clear away the block on the right side of the room to give yourself more runway if necessary. To escape the room, use the Morph Ball and roll through the passage on the floor. Bomb your way up to the door when you reach the end.
- Power Bombs A (room X)
- Enter room Q and drop down a short distance. You will see a ledge covered with thorns, and a small wall on the left. This wall can be broken with the Screw Attack. Pass through to find hidden room X. Run to the left across the thorns to reach a barrier with Power Bombs waiting on the other side. To remove the barrier, you must use a Power Bomb.
- Missile Tank J (room X)
- While collecting the Power Bombs in room X, you will probably notice the Missile Tank waiting in the passage by the ceiling. When using a Power Bomb to collect the bombs, you will probably also notice the Speed Boost tiles in the passage along the left wall. To reach all of this, you must visit the room below room X, room T where you found one of the Gamma Metroids. From here, you need to find the tile in the ceiling that is susceptible to Shinespark attack. The easiest way to identify that tile is to detonate a Power Bomb. Once you find the tile, note that it is directly above a ledge that is not far above the ground. The ground below that ledge is just long enough to run and build up Shinespark. Squat down to store the Shinespark, and then jump on the ledge. Stand on the right edge of it, and press jump to blast through the ceiling, and up into the passage in room X above. Then roll along the ceiling to obtain the missile tank.