Boiler Island is one of Gehn's strongholds in Riven. Luckily for you, he's not there when you arrive. Like much of the Age, Boiler Island has star🐭ted falling into disrepair, but with a little work you can ge🍷t the machinery back online and see what Gehn's been up to for the last three decades.

From the beach to the Fire Marble mines to the workshop, this guide will step you through all of Boiler Island's puzzles. There's a lot to learn as a ✨reward for making it this far, so be sure to check everywhere as you go!

How To Enter The Boiler Room

The mine cart from Jungle Island drops you off on a deserted beach with some dilapidated machinery. The main feature is a large, locked boiler room to your right. It needs power before you can do anything with it, so start by walking on the bridge out to the middle of the lake. There, you'll find a valve that rediܫrects steam power to the three main mechani𓆏sms.

Clockwise from the right, the valve powers the water pump in the mines, the boiler room, and the wood chipper near the mine cart. You need the boiler right now, so set the valve to the middle position and head back to the beach.

Climb the stairs to the Boiler Room door and walk around to the side where the pipes meet the building. You need to completely turn off the machinery so that the safety system will allow you to open the door. Start by turning the wheel on your left to drain the water from the chamber. Next, turn the valve next to the wheel, red🔴irecting power to the other side of the window.

Push the lever on the wall up to raise the platform inside, then finally turn off the gas by closing ⛄the valve to your right. With no water or heat in the building, and the platform raised, the light over the door will turn off, indicating that it𝓀 is safe to enter.

Go inside and climb down the ladder to reach hidden tunnels beneath the lake. They'll take you to a path behind the hill, which leads to the walkway you could see from the beach. Pull the lever next to the ladder to open a quick path back down.

How To Get Through The Mines

Before opening the door at the top of the cliff, climb down the ladder back to the beach and return to the power relay at the center of the lake. ⛎Return the valve to its original position, all the way to the right. You'll need to use the water pump it's connected to, and going now saves you a trip back later.

Go back up the ladder and through the door to enter the mines. Follow the path until you come to the pump, and turn it on by pressing the large button at the center. It will drain the underground lake, letting you climb down into the cavern below.

Immediately on your left after dismounting the ladder will be a pickaxe; use it to excavate a geode, which you can then place in the cargo bed of the nearby mine cart. Rotate the cart's crank counter-clockwise to bring it to the end of the track, then get off and look for another crank on the right. You can turn this clockwise to call the elevator from above.

As long as the cart is at the end of the track, it will automatically board the elevator once the lift is in position.

Board the elevator and pull the lever behind the cart crank. This changes it to operate the elev🦄ator, so you can now use it🐬 to ascend to Gehn's workshop.

What To Do In Gehn's Workshop

There are several key 🌃pieces of information in Gehn's Workshop. Be sure to take note of them all, either by writing them down in a note app or a physical piece of paper, or taking screenshots.

How To Find The Fire Marble Values

Take the geode and place it in the vice-grip on the workbench to the right. Turn🅠 the handle to break it open, revealing the Fire Marble inside. Place the Fire Marble on the striker device to the left.

The next part requires some experimentation, as the associated values are randomly assigned when you start a new playthrough. Adjust the strike force by moving the slider at the top of the device - it doesn't matter where for your first attempt, but somewhere in the middle usually works best. Then, raise the plunger at the top and press the button to hit the fire marble.

Note the position of the needle on the machine. You want it to land exactly in the center, in the green field. Adjust the slider to the left or right as necessary and keep striking the marble until you find the correct position. The number of notches from the left that the slider is located is the "base value" for this playthrough. Write it down, then consult the notes on the desk to the left.

Gehn has written down the necessary adjustments to create a power marble for each of the generators in the Golden Dome; again, these values are random with each playthrough. Using the D'Ni numbering system that you learned on Jungle Island, write down how much you need to increase or decrease the strike force from the base value 🅘based on Gehn's notes for each symbol. This information is critical lat🐟er.

How To Find The Missing Grave Totem Number

The workbench opposite the striker device has a part of a Rivenese grave totem like the ones you saw on Jungle Island. It looks like a wooden cylinder with nails around the top. If you look inside, you'll see metal wedges that correspond to the Rivenese number system t🍷hat you partially learned in 🅘the schoolhouse, but as Gehn's journal notes you need to know the orientation of the cylinder to determine the number value.

Use the looking-glass that you got from the beach on Jungle Island to see the invisible marker on the rim o♕f the cylinder. This denotes the top, which you can use to determine which number s𓆏ymbol is inside. Note it down for use later.

What To Do With The Marble Polisher

The mechanism at the center of the room is polishing a Fire Marble. You can start and stop the machine with the lefꩵt-hand lever, and power the gears with the right-hand lever. The right-hand lever needs to be pulled every now and then to keep the machine running.

The machine isn't important to the story, but if you watch it work for fifteen minutes on a single playthrough, operating the levers to keep it working, you'll earn an Achievement /ꦯ Tr🌟ophy.

The fifteen minutes don't need to be consecutive, but if you're looking to complete your collection you may as well just get iౠt all in one go.

Where To Go Next

Optionally, you can read Gehn's journal on the table next to the mine entrance. It's long, but contains key information about his plans, and how you might be able to escape Riven. The door that you need to leave by is between the journal and the table with the totem piece. Unlock it and st༒ep out onto the walkway over t🏅he cliffs.

The right-hand path is a dead end; take the left path back to the mine entrance. Opening the door from this side reveals that it's actually a four-way intersection, and you can go ♉down a set of stairs that you probably didn't see when you pa♚ssed through the first time. There's a rotating sphere here, similar to the one on Temple Island.

To enter the sphere, you need to stop its rotation using the zoetrope device visible in the wall to the left. Stand in the doorway and close the door, revealing a side passage. The zoetrope must be stopped by pressing the top button on the symbol associated with Boiler Island for this playthrough - note that the timing has to be just right. You can find it by looking at the window overlooking Boiler Island from the Golden Dome on Temple Island, but there's an easier way if you don't want to go all the way back to the beginning of the game. If you look at the rotating sphere through the viewing glass, you'll see an otherwise-invisible mark indicating the correct symbol. No𓆉te it down this time, and match it to the value that was wrꦺitten in Gehn's notes back in the lab.

If you'꧟re not a hundred percent sure what the number was, it doesn't hurt to take a quick trip back to the lab and double-check Gehn's notes if it means you'll save a longer walk later.

When you're ready, enter the sphere to continue your journey.

Alternately, you can leave Gehn's workshop by the other door and take the tram to Survey Island. I⭕t's better to use the sphere first, though, as powering it on and taking a quick trip to Prison Island lets you activate both as teleport locations from the other islands' spheres.