Underground Lab & Escape

Push through to the double doors ahead — the far elevator has no power yet. In the machine room beyond (a storage chest and Green Herb here), push the metal crate onto the elevator and ride it down, then keep pushing it right until it lines up with a stack of crates further down the hall (not needed yet). Check a zombie's corpse for the P-Epsilon Gas Report file; further on there's a typewriter, Ink Ribbon, and Shotgun ammo. Take the next elevator down to find two Evolved Lickers guarding a power panel — clear them and activate it to restore power to the lab's elevator, then ride the original elevator back up.

Back at the platform with the giant elevator, clear five zombies. The security office door is locked for now. Take the left door into the generator hallway (it still needs a part), then through the door with blue lighting into the east area.

Past the double doors, a freezing room holds a First Aid Spray and a Fuse Box — use it on the central machine to assemble the Main Fuse. Bring it back to the generator hallway and use it there to restore the lab's power.

Take the door with red lighting into the west area. At the end of the hall is a dormitory — the computer holds the security manual file, and a chair has the Lab Keycard and User Registry file, revealing a username:

The locker here has a Flame Thrower, and there's a planter with Blue Herbs. In one corner, a vent leads to a room with two more Evolved Lickers (Shotgun ammo and Ink Ribbon on a desk once they're down).

Back in the hallway, open the blinds to face two Ivy plants — poisonous if you released the gas earlier, either way the Flame Thrower clears them easily. Continue to the stairwell area (a third Ivy plant and two Green Herbs here). Down the stairs, clear three Evolved Lickers along the corridor (three Green Herbs), then reach a control room with monitors — the lit one shows the Lab Map. Grab the Weapons Locker Key from the chest.

Take the right door into another hallway, then left through a door needing the Lab Keycard to reach a room with a giant moth. Kill it and destroy its larvae, then use the computer:

Two Scenarios, One Login

If you already registered GUEST in Claire's playthrough, do it again here with Leon — this is what unlocks the sealed doors ahead. If you haven't yet, registering now still lets you continue.

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Back in the east area, activate the blinds by the sealed double doors and register your login on the computer beside them to unlock the way through.

Inside, clear three Evolved Lickers, and check a soldier's corpse for a Sub-Machine Gun — or just ammo for it, if Claire already picked one up in her own run. Use the Lab Keycard on the central door (it's consumed) into another lab with two Ivy plants — clear them, flip the wall switch for light, and grab Magnum ammo from the gurney.

Use the Weapons Locker Key on Lab P-4's lit locker for the Magnum Part (adds power at the cost of heavier recoil), clear the five zombies inside, and take the Power Room Key from a desk.

With the Power Room Key, head back toward the machine room — Annette ambushes Leon along the way, fleeing when the Tyrant shows up. Evade or knock it down (Magnum ammo if you do) and continue to the machine room where you pushed the metal crate earlier; climb it to reach the power room. Use the key to open its door (discarding it), and the Tyrant corners Leon inside — Ada arrives and attacks it; the Tyrant loses its grip and falls into a pool of molten metal below. Ada is wounded in the struggle and apparently dies there too.

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Take the Master Key and pull out of the area, leaving Ada behind.

Outside, the Tyrant somehow survives the fall. Claire radios in, asking Leon to find Sherry in the security office (on the giant elevator platform), and the lab's self-destruct alarm starts blaring. With the Master Key, return to the giant elevator platform and open the security office — Leon carries Sherry to the elevator. Inside, use the Master Key on its panel to activate the escape route.

At the bottom, Leon carries Sherry onto a subway train. Head to the rear cabin (storage chest, typewriter, Ink Ribbon, and the Platform Key on the floor). Grab your strongest weapons and healing items, along with the Platform Key, and step back out.

Use the Platform Key on the locked door — a walkway and storage chest await, and a 5-minute countdown starts before the lab detonates. Cross the walkway, flip the wall panel's switch, and grab the Combined Plug S and Combined Plug N. Take the door near the stairs to a platform and place both plugs in the wall panel to power the train.

Powering the plugs brings the Tyrant back in a faster, more dangerous form.

Tyrant T-103 (Final Form)

Dodge its attacks and fire back from a safe distance — stray too far and it charges. After a while, Ada reappears and throws Leon a Rocket Launcher; use it to finish the Tyrant off for good.

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Rush back to the platform and clear five zombies along the corridor to reach the gate control panel — activate it to open the train's doors, then board and start it from the driver's cabin.

With the train moving, a cutscene shows Claire arriving just in time to board, the lab exploding behind her, and Claire giving Sherry the vaccine. An alarm cuts the moment short — head to the rear car; the door to the main car seals behind you, and a 2-minute countdown begins before the train itself explodes. A disfigured William Birkin appears in the rear car.

William Birkin (Final Form)

Stay as far back as you can and open with the Rocket Launcher, then finish him off with the rest of your arsenal. After enough hits, he's finally defeated.

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Return to the main car for the ending cutscene: the survivors bring the train to a stop and escape moments before it explodes, taking Birkin down with it for good.