Task 1: Getting the Boomerang
The first room in the temple contains a caged monkey. Destroy her cage, and she will climb some vines, beckoning you to follow. Use your slingshot to destroy the spiders, then go into the next room.
Once in the next room, advance to the platform in the middle. A huge spider waits there. Attack its backside with several fast slices or a jump attack. Once the spider is gone, light the platform's four torches to make a set of stairs appear. Climb them and retrieve the dungeon map from the treasure chest.
Bad Baboon, Good Ooccoo
The monkey will lead you to the room to the north. After you watch a baboon use a boomerang to cut down the bridge, you'll return to the previous chamber. Use the help of your simian pal to get to the west door. Just jump at the monkey when it is near you, and let go when it is by the other side.
You can turn the spiderlike enemies into bombs by either hitting them with your shield or sword. Since you will have to put the sword away in order to pick them up, use your shield to activate them. Use one of these enemies in the west room to destroy a weak section of the northern wall. You will meet a creature named Ooccoo, who will warp you out of the dungeon from any spot outside of the boss chamber, and then warp you back inside when you are ready to return.
Save A Monkey
Your pal will encourage you to go west to a locked door, but you need to go north first to get the key. You'll find it in a chest after you cross a rotating bridge. Return to the monkey, defeat a hanging spider, and advance to the west.
A caged monkey waits on a pillar in the room on the temple's west side. Roll into the pillar three times to knock it over. Defeat the enemies, then use both monkeys' help to swing over a gap to escape the room.
Go back to the room where you found the dungeon map, and use the monkeys to cross over to the eastern section into the killer-plant chamber. In the next room, defeat the carnivorous plants before they chomp you. Then, advance onto a wooden platform. Use your shield to turn the spider thing into a bomb, and throw it into the gap where a toothed plant waits at the North end of the room. Then use one of the spider bombs to blow up the big rock. You do this by jumping on the moss (after you use your slingshot to kill the bugs. Next, take the bomb there and drop it over the edge blowing up the Southern toothed plant. This will give you access to piece of heart #2. Then head to the door in the South.
In the southeastern room, you'll face off with a very large plant. After you enter the chamber, the plant will swallow the key. Target the roaming bud, dodge it when it lunges at you, and counter with a jumping attack. After it's gone, use a bomb to destroy the rest of the growth, then collect the key. Free the monkey from the southern section of the room before you leave. Continue to the East door.
East of the killer-plant chamber, behind the ruins of the boulder in the room between the two dead ends, you'll see a monkey in a locked cage. Enter and walk down the stairs on the northern side. Roll into the totem pole at the base of the stairs to knock a chest to the ground, then collect the key from it, and advance eastward. Swim across the water (using the logs) to prevent enemies hiding under tiles from throwing you, light the lanterns to make steps appear, then climb up to the monkey. Defeat the Skulltula there, then free the monkey. Once you have the monkey in tow, return to the room where you found the dungeon map.
Advance through the north door and use the four monkeys to cross the large gap in the temple's largest chamber. Go through the door to encounter Ook. Ook jumps from post to post, sometimes stopping to release the boomerang. When it does so, roll into Ook's pillar. A square hit will knock Ook down, allowing you to hit its red behind by Z-targeting and pressing A.
After a few rounds, Ook hops towards the center of the room, but accidently hops into a pillar. The parasite is knocked off, and it dies. Ook returns to normal and escapes the room, and the Gale Boomerang will become yours.
Task 2: Saving the Monkeys
The Way to the Compass
Use the Gale Boomerang to spin a turnstile above the exit three times to raise the gate in front of the door. Leave the room then spin two bridges to cross a gap in the east. You'll discover a monkey in a cage that is suspended by webbing. Hit the webbing to free the monkey.
Return to the central room, the one where you found the dungeon map, a use the boomerang to free a treasure chest from the webbing. Open the chest to collect the compass, a handy item that shows the location of the treasure chests, caged monkeys, and the boss of the dungeon.
Return to the room east of the killer-plant filled room and use the boomerang to uproot the tile enemies. Extinguish the torches in the area to lower the stairs, which gives you access to piece of heart #3. Most of the remaining chests contain rupees.
The Big Key
Travel west to the large gate and four turnstiles in the room west of the central room. A flight path on the ground connects the turnstiles in a zigzag pattern. Use the boomerang to hit the turnstiles in that pattern to make the gate open. This is done by targeting with "B" over the furthest right turnstile, select it with "Z", still holding "B" continue to select each turnstile till all four are targeted with a pink or orange target then release the boomerang. The treasure chest inside contains the big key, which unlocks the door to the boss chamber. Try to avoid hitting the bridge, If you do there are ways around it just a bit more difficult.
Travel north past the west side of the temple's largest chamber. Hit the turnstile with a boomerang blast to straighten out the bridge section. When you're on the bridge, hit the turnstile again. The bridge will span east and west. Go east to a room where there are spiders and three holes in the floor (two covered by webs). Burn the web, by hitting "B," that covers the hole on the northern side. After you fall through, you'll land on a stump next to a caged monkey. Destroy the cage to free your new friend.
Rotate the bridge so it spans north and south, and go north to the room that houses the saved monkeys. Manipulate the room's bridges to reach the east side. Destroy the spiders on the vine with your slingshot or boomerang, then climb to the top.
Go east into the next room. There is a bomb spider on an floating log at the north end of the room. Hit it with the boomerang to retrieve the bomb, and toss it into the vase-like plant. After the plant is gone, you'll have access to a key.
A rock blocks the way to a trapped monkey. Use the gale boomerang to carry a bomb to the rock and clear the way (target the bomb spider first and the rock second). Climb the vines to reach the eastern alcove and destroy the enemies there. Use your boomerang to retrieve another bomb, and toss it at the boulder in the alcove to free the monkey. Return to the Eastern room then back to the south room with the one bridge.
The Last One
From here use your small key to enter the westernmost room. There you'll find some tile enemies. Use the boomerang to uproot them, then proceed to the north side of the room. Hit two turnstiles with your boomerang to release the last monkey.
Return to the room that houses the freed monkeys. They'll form a single swinging line. Hold onto them to cross a very large gap. On the other side, break a pot to either collect or bottle a fairy, then proceed into the boss room.
Twilit Parasite: Diababa
The battle begins with two giant buds emerging from the poisonous goo. Target bomb spiders then buds to deliver explosive charges to them.
When the buds have sustained enough blasting, the main creature will show itself. It will attempt to cover you with a purple liquid. Sidestep the mess and wait for the now good baboon to enter the picture. The baboon swings through the room while holding a bomb. Target the bomb then Diababa's head and release the boomerang. After suffering a direct hit, Diababa will fall to the ground and stick out its toungue, revealing an eye at the tip. Hit the eye with your sword until it recovers. Diababa will fall after a few rounds, giving you a heart container and a fused shadow. You can also use the ending blow on Diababa when it falls to the ground.