Fireboy & Watergirl
Friends · LEVEL 15 · Verified walkthrough
The Low Tunnel Relay
Small and Heavy free the heroes together. Use Heavy to reach the right-hand shelf, raise green for Fireboy, then move Heavy across the lava on the pink ferry. His head is the final step over the wall beside the exits.
Level objective
Bring Fireboy to the orange exit in the lower right and Watergirl to the blue exit in the lower right. Both heroes must be at their own doors together. The 8 unmarked diamonds are optional; collect every diamond for a perfect clear.
| Campaign | And Friends · 15 of 36 |
|---|---|
| Collectibles | 4 fire diamonds, 4 water diamonds. 0 marked diamonds required; 8 optional. |
| Hazards | 1 lava pool, 1 water pool. Only your own element is safe; purple goo is dangerous to both. |
| Mechanisms | 4 plates, 1 lever, 5 moving platforms |
| Win condition | Bring Fireboy to the orange exit in the lower right and Watergirl to the blue exit in the lower right. Both heroes must be at their own doors together. The 8 unmarked diamonds are optional; collect every diamond for a perfect clear. |
| Exits | Fireboy: lower right. Watergirl: lower right. |
Step-by-step walkthrough
Open the narrow tunnel
Small walks right beneath the blue gate and holds the blue plate. Heavy can now follow through the open passage.
Put Small on Heavy’s head
Move Heavy near the left end of the short right-hand shelf. Small continues right, jumps left onto that short shelf and walks off its left edge onto Heavy’s head.
Carry Small back left
Heavy walks left until he is beside the end of the long shelf above. Small jumps left from his head onto that shelf. Heavy steps right off blue so its gate lowers out of Small’s upper route.
Free both heroes
Small walks left to the orange lever. Once its gate opens, Fireboy and Watergirl can walk right from the starting shelf. Watergirl collects the blue diamond on the next shelf.
Help Watergirl reach the upper-right shelf
Place Heavy on the right side of the green lift while it is down. Watergirl drops to this floor and jumps onto his head. Stand clear of the upper shelf’s left edge, jump up first and steer right onto it.
Collect right-hand blue and hold green
Watergirl walks off the upper shelf to the right, collecting blue as she drops into the water below. Walk left through the pool, jump out over its left lip and hold the green plate.
Collect the roof diamond
Fireboy jumps right from the left shelf onto raised green, then right onto the upper shelf. Stand just left of the sloping roof edge, jump up before steering right, and collect red on the roof.
Drop into the middle
Fireboy returns left to the upper shelf, drops left to the floor below and walks into the opening beneath raised green. He collects red while dropping to Watergirl’s ledge. Walk left down the short slopes for the next red diamond.
Collect the left blue diamond
Watergirl follows left down the slopes, jumps across to the left shelf and jumps up and left onto the small ledge beneath the long starting floor. Collect blue.
Collect the lava diamond
Fireboy drops left from the middle shelf into his lava pool. Walk left for red, jump right out of the pool onto its bank and continue right to hold the yellow plate on the bottom floor.
Bring both friends downstairs
Watergirl returns across the left shelf and middle slopes to hold green again. Small walks right from orange, drops to the middle floor and enters the opening beneath raised green. Heavy steps left off the raised lift, drops to that floor, then walks right through the same opening.
Move Small to yellow
Small walks left down the middle slopes. Ease off the shelf’s left tip slowly, then steer right while falling onto the pink ferry. Jump right onto the lava’s dry bank and walk right to yellow.
Raise Watergirl to pink
Watergirl drops left from the middle shelf and steers right onto the ferry. Jump to the dry bank and drop to the bottom floor. With yellow held, stand just left of its lift, jump up first and steer right onto it. Both Fireboy and Small step away from yellow. Watergirl rides up and walks left onto pink.
Ferry Heavy safely across the lava
Once pink has moved the ferry left, Heavy walks left off the middle shelf onto it. Watergirl walks right back onto the yellow lift, releasing pink. Let the ferry carry Heavy right; he walks across the dry bank and along the bottom floor into the narrow recess beside the exit wall.
Collect the last blue diamond
Small holds yellow to lower Watergirl. She steps left off the lift, drops to the bottom floor and walks right beneath it to Heavy. Jump onto his head and jump again for the blue diamond overhead.
Climb the exit wall
Each hero jumps from Heavy’s head towards the sloping top of the wall on its right. Jump up before steering right so the wall does not stop the ascent. Watergirl can wait beyond the wall, clear of her door, while Fireboy follows.
Enter both matching exits
Walk down the right side of the wall to the matching doors. Fireboy’s door is nearer the wall; Watergirl’s is farther right. Wait until the first hero is standing inside, then bring the other hero in. Either exit order works.
This route was verified in the game simulation using player controls, required diamonds, and both matching exits. It describes this version’s independently reconstructed room, not an official walkthrough.
How this room’s mechanisms work
Switch 1
middle center
Keep a hero or movable weight on this plate to keep its signal active. Stepping off releases it.
Controls Moving platform 2.
Switch 2
upper left
Walk past the handle, or use it nearby: Enter for Fireboy, E for Watergirl, or the touch Use button. Each use toggles it; it stays set after you leave.
Controls Moving platform 1.
Switch 3
middle center
Keep a hero or movable weight on this plate to keep its signal active. Stepping off releases it.
Controls Moving platform 3.
Switch 4
lower center
Keep a hero or movable weight on this plate to keep its signal active. Stepping off releases it.
Controls Moving platform 4.
Switch 5
lower center
Keep a hero or movable weight on this plate to keep its signal active. Stepping off releases it.
Controls Moving platform 5.
Moving platform 1
upper left
At least one of these inputs must be active: Switch 2.
When powered, it moves up; when power is released, it returns.
Moving platform 2
middle center
At least one of these inputs must be active: Switch 1.
When powered, it moves up; when power is released, it returns.
Moving platform 3
middle center
At least one of these inputs must be active: Switch 3.
When powered, it moves up; when power is released, it returns.
Moving platform 4
lower center
At least one of these inputs must be active: Switch 4.
When powered, it moves left; when power is released, it returns.
Moving platform 5
lower center
At least one of these inputs must be active: Switch 5.
When powered, it moves down; when power is released, it returns.
If you get stuck
Check the unfinished objective
The diamonds in this room are optional. If you only want to finish, bring both heroes fully inside their own matching doors.
A gate or platform moved back
A pressure plate releases when its rider or weight leaves. Keep your partner on it until you are safely across. Levers stay set after you leave; check their ON or OFF state before crossing.
You missed a moving platform
Return to safe ground and use the connected switch to bring it back. Board before your partner releases the plate or changes the lever. Avoid jumping into its underside; line up with the open shaft first.
You cannot recover safely
Pause and choose Restart level to reset both heroes, diamonds, weights, and switches. Previously completed levels stay saved. Follow the step order before moving a box or releasing a weight.
For touch controls, jumping, audio, or online connection problems, see player troubleshooting.
Level questions
How do you finish The Low Tunnel Relay?
Small and Heavy free the heroes together. Use Heavy to reach the right-hand shelf, raise green for Fireboy, then move Heavy across the lava on the pink ferry. His head is the final step over the wall beside the exits. Bring Fireboy to the orange exit in the lower right and Watergirl to the blue exit in the lower right. Both heroes must be at their own doors together. The 8 unmarked diamonds are optional; collect every diamond for a perfect clear.
How many diamonds are required in The Low Tunnel Relay?
8 diamonds: 4 for Fireboy and 4 for Watergirl. None are required to finish. 8 unmarked diamonds are optional collectibles for a perfect clear.
Which hazards are in The Low Tunnel Relay?
1 orange lava pool (lower left) and 1 blue water pool (middle right). Fireboy can enter orange lava; Watergirl must avoid it. Watergirl can enter blue water; Fireboy must avoid it. If either hero falls into a dangerous pool, both players restart the level.
What do the switches do in The Low Tunnel Relay?
Switch 1 (middle center): Controls Moving platform 2. Keep a hero or movable weight on this plate to keep its signal active. Stepping off releases it. Switch 2 (upper left): Controls Moving platform 1. Walk past the handle, or use it nearby: Enter for Fireboy, E for Watergirl, or the touch Use button. Each use toggles it; it stays set after you leave. Switch 3 (middle center): Controls Moving platform 3. Keep a hero or movable weight on this plate to keep its signal active. Stepping off releases it. Switch 4 (lower center): Controls Moving platform 4. Keep a hero or movable weight on this plate to keep its signal active. Stepping off releases it. Switch 5 (lower center): Controls Moving platform 5. Keep a hero or movable weight on this plate to keep its signal active. Stepping off releases it.