Level 19. Water Torture (2)

In the bedroom containing a vacuum cleaner, locate the door situated between the second and third bed. To open this door, you must first flood the chamber by shooting the rank (a type of pipe or valve) near the window. Once the room is underwater, you can access the door. Inside, retrieve the nuke, float to the top, and shoot the two air vents to collect the items hidden within.

In the room featuring two columns on a "light red" platform, activate the light by shooting the light switch. This action will cause the column to sink, revealing a rail gun.

After using the laser tank to destroy the metal door and create a hole in the far wall ahead of you, proceed all the way up and outside to the area where the submarine is circling the island. Consult your map (minimap (the small circular map in the bottom-left corner of your screen)) and navigate to the northwest pillar or chimney. Face this structure. Descend and pass through the hole in the wall to find a guardian head.

Upon acquiring the yellow key, proceed to the yellow key lift and descend. Exit the lift and then send it back up. A panel on the east side should open, granting access to some items.

After obtaining the blue pass key, go to the blue corridor. In the northeast corner, a panel can be opened to reveal some items.

Check behind the end-level switch to find a heat seeker card.