Before heading toward the next upgrade, there are still still a couple more expansions to get. If you're entering Sanctuary Temple from the main entrance these will be right on your way, but if you're coming from Agon, as we left off on the last page, you'll have to backtrack a bit. If so, head back through the Reactor Core, save if you want, and continue back to Sanctuary Entrance. There is an Ingsmasher waiting for you in Reactor Access, but that fight will occur whether on your way out or on your way in. Now that you have both Burst weapons, the Ingsmasher should be no problem provided you use the right attack at the right time.
Look for a cracked window to the left of the door to the Power Junction and break it with a Power Bomb. Go inside, step into the lift, and scan the panel on the upper floor; this activates an Orb Cannon. Take the lift back down an use the cannon to be shot to a platform in the middle of the chasm.
There are two Spider Ball tracks, one going up and one going down, leading from the little terrace you find yourself on. Start by Spidering up to the top of the platform where you'll find a cannon similar to the ones in the Central Mining Station back in Agon. Before using it though, take a look around to see what you're going to be shooting at. Switch to Scan and locate the weak section of rock near the top of the cliff face above the door leading back to Temple Grounds. (They are to far to actually scan from here but they should glow in the scanner.) Second find a stack of giant crates in a similar position on the opposite side of the chasm. The third target is easy to miss; it's a weak section of rock below and to the right of second target, sticking out from the side of the Temple. Get into the turret and fire at the three targets, it should only take one shot each.
Spider back to the balcony and down again to a second orb cannon which fires you to the room where the lift took you earlier. Take the lift down again and go to the right of the Sanctuary door. Scale the ledges to find a hologram to scan and a Spiderball track uncovered when you blasted the rocks. Follow the Spiderball track to the top, scan the Luminoth there, then roll into another Orb Cannon to be shot clear across the chasm to a ledge in the cliff. Somewhere around this point is where you should reach the 80% scans milestone. Pick up the Power Bomb Expansion here. Getting down from here is a bit scary, but you should be fine if you just drop off the edge.
Main Gyro Chamber
Head back to the Main Gyro Chamber, first by returning across the chasm via Spider Track and heading to the Reactor Core. A Rezbit may have replaced the Ingsmasher in Reactor Access. You may notice that we're passing a Yellow Door in Reactor Core and there is another in the Dynamo Works where we fought the Spider Guardian, but we will come back to these later. You can save your game here, or when you reach the Main Gyro Chamber, since we're coming up on another boss. Use the Minigyro Chamber & Hall of Combat Mastery to reach Central Area Transport East, which will lead you to the Main Gyro Chamber.
Take the lift next to the white door as before, but this time stay in the upper room and scan for some debris next to the window. It's made from Denzium so blow it up with a Power Bomb; a Bomb Slot appears. Activate the Bomb Slot to activate a puzzle almost exactly like the one one the lower level, so solve it the same way. One solution is
- Lower right, Lower left, Lower right, Upper left, Upper left, Lower left, Upper left, Upper right
Again, when the puzzle is solved another Bomb Slot appears and this one stops the inner ring of gyroscope to stop.
Enter the gyroscope room as before and notice that the outer edge of the small ring is really a Spiderball track, so follow it from one end to the other and Boost jump off. This throws you through a cracked window into a room with a Yellow door. Blast open the door and proceed to a new area.
When you enter the room you see Dark Samus fighting some Pirates, defeating them handily, and going after some Phazon. (So much for the 'The enemy of my enemy is my friend' logic; Dark Samus, the Ing and the Pirates all seem to hate each other at least as much as they do you.) Head right, through a doorway that opens as you approach, into a side room with storage crates. Another doorway opens to the room where Dark Samus was, but she's gone now. Shoot the crates to stock up on supplies and continue.
Aerie Transport Station
So you're powered up, Dark Samus is powered up on Phazon, so it's time for a battle. Step into the room, actually a giant elevator, and Dark Samus will stop absorbing Phazon to start the elevator going up and try to defeat you before it reaches the top.
The battle takes place in the elevator shaft and continues after you reach the top.
The battle with Dark Samos continues here and when it's over Dark Samus breaks through a window and falls out, but since she returned after you blasted her to smithereens in the last battle, a little thing like falling a few thousand feet isn't going to get rid of her permanently. Now it's time to collect your reward, but Dark Samus didn't just leave it behind; you have to solve a puzzle to get it.
Look out the broken window to find a narrow ledge around the outside of the room. Follow it to a small room with a portal and go through.
Hive Summit (Dark side)
Gather health from the Ing Caches near the portal and follow the ledge back. If you're still low on health at this point then you'll want to heal up a bit in the Light Beacon about half way along; safe zones may be hard to find here. When you reach the end of the ledge, Spider up and over the wall into the main room. (The window in this version of the room is not broken.) Now it looks like you just have to follow a Spiderball track here, but you'll find it's a dead end. The trick is to first use the Spinner to rotate the track around first. Now when you follow the track you can to a Boost jump at the end to reach a ledge with a safe zone. Heal again if you need to and hop over to the platform in the middle where a portal is waiting.
Hop over to the ledge and grab the Echo Visor. As usual, the game wants you to use the new item to escape. Switch to the Echo Visor and look for the sonic waves being emitted from three pillars here. The beams themselves show up as a cone of bright circles, the locks they hold in place show up as lock icons, and the emitters show up as orange speaker icons. You can lock onto the emitters while using the Echo Visor, so shoot them to disable all three locks. A hologram appears, so step into it to be carried back down. Continue back.
Checkpoint Station (cont.)
Another set of sonic lock has appeared here and you must disable it the same way in order to get out. This time there is only one emitter and it's aimed directly at one of the doors. You should now be able to reach a Save Station without further trouble.
Expansions (Sanctuary Temple)
We'll be getting just one expansion here; there are more you can get but they will be covered in future exploration.
Return to Temple Access, defeat the Rezbits there, and use the Orb Cannon to get to the ledge again if necessary. Use the Echo Visor to locate the sonic emitter on the central structure and shoot to disable it. When the lock is disabled the backstop you hit when you fire the Orb Cannon is moved forward over the central structure. This one will restore itself eventually so you have limited (but still generous) time to do what comes next. Drop to the lower part of the room and use the Orb Cannon, but with the backstop in its new position, instead of landing on the ledge you'll find yourself in a channel through the structure leading to a space under the floor. Get the Missile Expansion there, then use the Spinner to open a way out.