Shaking Door

And now the real fun starts. Lara has been chased into an old apartment block. She has closed the door behind her, but her pursuers are already rattling at the doors. Pull and push the wardrobe in front of the shaking door. This will gain you some time when climbing the stairs. The other door down here and the lift are both useless for now.

Gas Attack

Run up the stairs. If you did not pull the wardrobe in front of the door, the door will burst open as soon as you reach the first landing! On the first floor you will only find barred doors. A few steps further up, the door below will open and three guys appear. Two stay at the front door, one will come in. They will attack with gas. The air is getting thinner, so watch your air-bar. Run further up and ignore the barred doors. Instead jump over the gap in the stairs. If you linger downstairs or drop through the gap it might become necessary to fight the single attacker. Some kicking and punching will do the trick. But under no circumstances return to the main door, the guys there will take you prisoner and the game ends. Run further up to the second level. A boulder falls down from the roof and opens a huge gap in the floor. The door nearby (Apartment 21), in the passage on the left, is closed and you will need a key. Take a running jump over the new gap. Depending on where you jump over, it might be necessary to grab the ledge and pull up.

Muscle Training

Careful, the gas is getting thicker again. In the next passage on the left you can find some Health Pills, all the doors are barred. Continue up the stairs. Now you have to move the wardrobe out of the way, pull it. Run further up the stairs. In the next passage you can find a Small Medipack. The door here can be opened; Lara will force it open with her shoulder. As a result she will feel stronger. Power UP (upper body strength) The air in here is fresh and clean, but not for long. Open the wardrobe on the left to find some V-Packer Spread Cartridges. In the second wardrobe, on the right side of the room, you can find a K2 Impactor Battery. Run back outside and further up the stairs. In the next passage you will find Health Bandages.

Keys

Run further up to find the next part of the stairs blocked. You cannot jump over the rubble. Look at the crate in the corner of the previous landing. Pull and push it towards the lower part of the stairs. If you aren't strong enough to move it, run back down to the door you can run in to gain the upper-body-Power-up. Then climb onto it, facing down the stairs and take a running jump towards the railing above. Hold on and pull up. Open the door on the right and step inside. On the floor you will find the Lift Maintenance Key, which will give you access to the roof. You could exit now, but there are still some goodies to find in the locked apartment below. Take a close look at wall. There is another key on the board there, the Apartment Key for Apartment 21. Now use the switch on the right wall to activate the lift in the hall.

Apartment 21

The apartment key can be used on the second floor. This next part can be solved with the lift or on foot:
on foot:
Get outside and climb back over the railing and run down till you reach the gap. Take a running jump to the other side or drop down and run up the stairs.
using the lift:
Step back outside and run towards the open lift. Step inside and press Number 2. At your destination, run to the left and take a running jump with grabbing the ledge over the gap. If you want to avoid this jump press Number 1 and run up the stairs. You still have to jump over the small gap. Careful, if you drop down you have to fight one of the men.
Open the door you will find on the second floor by using the key. Inside you can breathe again. In the blue wardrobe on the left you can find a Vector - R35. In the desk drawers you can find a Chocolate Bar on the left and V-Packer Standard Cartridges on the right.

Exit

Now make your way back up to the top (either on foot or by using the lift to Number 4) and return to the chamber where you found the keys. Exit through the door.