This is the first level of the game, and doubles up as the tutorial.
After the introduction, you will eventually get to your feet in a small, icy area, with the cave opening in front of you. Turn around and look for a small hatch at the bottom of a wall and open it. From here, you're following what amounts to a simple corridor, until you reach something of interest.
The first body shows you a flashback of what happened during your trip - you've fell to the ground.
The second body shows your dogs stopped and barking at a ship, and you falling down (which teleports you across to the other platform.)
The third body shows you travel on the sled to where the dogs stop and bark.
The final body returns you to where you fell down. The dogs are present, and barking at you to help find the way. Turn around first, and collect the paper - after you finish reading it (the narrator continues reading after you put it away), climb the slope. Follow the dogs, going to the left and jumping carefully onto an ice platform. The dogs lead to a second ramp, which lead to the entrance of the ship - when the entrance is in view, the ramp makes a sharp turn, which lets you jump into the swinging cage outside the hull.
After the final flashback, you can proceed down the ramp, and open the hatch on the left. Climb the stairs, and reach the generator room. Flip the switch on the wall, and you'll restore heat to the current room.
You can either jump past the corpse and ladder blocking the pathway, or backtrack to the previous room to learn about the heat mechanism. If you backtrack, you get a change to warm yourself up at the fire, before an enemy tries bursting down a door. Return to the generator room and head to the top of the room before the enemy catches up.
The second door of the generator room is covered by a lock and chain, your first melee weapon. This is used in combat, as well as to burst open doors. You can pass through the doors ahead of you, and smash the boards away. The next room will show someone trying to hold a hatch closed, before snapping back to reality where an enemy attacks (from where the person was). You can use the basic punch to knock out the enemy. Flip the switch in the corner, and warm up on the lightbulb before proceeding.
The next room has two wooden beams blocking a hatch. The flashback will show two people setting up the beam, and returning to the present will have the enemy attack from the right. Warm up on the light bulb, and jump on the platform. The next enemy will appear when you approach the corner.
The next flashback shows water flooding the ship. Warm yourself up at the light bulb, and attack the enemy that bursts out of the ice in the next room. There will be no more encounters in this level.
The final part of this level involves a man frozen in ice. This introduces you to the mental echo, where you revisit the person's history and try to correct the mistake. When you enter the person's mind, quickly turn around and go through the door. Climb the ladder, and quickly reach the top. Enter the door. Run on the outside edge of the catwalks (as the innter portions will quickly collapse), and open the door. Approach the man holding the door open, and you'll successfully rescue the person and unblock he path.
The following room shows the cutscene of the captain and first mate discussing the detection system. The captain ultimately disagrees with the scientific equipment, and relies on gut feeling instead. When the scene finishes, continue on the walkway, and open all the handles on the door (which requires the flashlight to see properly.)