After a speech from our old "friend", the G-Man, you'll appear on a train inbound to City-17. As you'll soon discover, City-17 is a sprawling city under the firm grip of the Combine. It also serves as headquaters for Dr. Wallace Breen, former Black Mesa Administrator. A few seconds after you gain consciousness, the train comes to a stop in the City-17 terminal and you disembark with a few others. A hovering scanner will take your picture — don't worry these scanners are relatively harmless (though they may alert reinforcements later on). Follow the other passengers to the left of where you disembarked. Go left and you will see a Combine Soldier beating up a civilian. Continue through the metal turnstyle and take the dark passage to the left come which will take you to the waiting lounge. Take the route through the fenced aisle until you reach the Combine security checkpoint. A Combine solider will ask you to follow him down the passage to the right.

The Combine soldier turns out to be none other than Barney Calhoun, the friendly security guard from Black Mesa. After a quick word with Dr. Kleiner, Barney will ask you to exit through the back door and make your way to Kleiner's Lab. In the adjacent room, climb the ladder to get to the upper landing and pick up a few boxes and place them near the window to jump from it ('E' is the default key to pick up objects). On landing, proceed through the door on your right. Climb up the staircase and take a left. The Combine soldier asks you to pick up a can and throw it in the bin. Will you show your defiance and throw it at his face? Not if you don't like being knocked to the ground with a stun-baton.

After that little stunt, proceed ahead where you will be subjected to some more pro-Combine propaganda, courtesy of Dr. Breen. Forge ahead and take the exit on the left. Open the door and behold the beautiful City 17. Don't bother trying to get through any of the checkpoints or doorways, they're all locked for the time being.

Facing outwards from the door (from which you entered the city square), take a right and keep moving straight. You should see a Combine check point and a Strider t on your left as you proceed down the street. Turn right into the alley and climb the ladder there to scale the fence. Jump onto the crate on the other side of the fencing. The crate below should cushion your fall. Continue ahead and take a right and you will see two citizens discussing, you guessed it, those darstardly Combine. Move straight ahead and go through the door on your left.

Move through the hallway and up the narrow staircase. After two flights of stairs, take a left and wait for the Combine soldiers to move on. Continue ahead and enter the first house on the right. You will see two civilians looking out the window, seeing the Combine Forces approach. Waste no time and exit go through the glass door exit. Move up the dark stairway and to the next floor. A civilian asks you to get into his house. Do that and make your way through the house and exit from the back door.

The Combine soldiers are now after you, so you need to quicken your pace through the next section. Quickly move up the staircase as two Combine soldiers will start chasing you. Enter the door on your right and move up the smaller staircase.

image: http://www.hlfallout.net/image.php?id=31127

image: http://www.hlfallout.net/image.php?id=31126

You enter a large empty room once up the stairs. A Combine Helicopter is already shooting at you as you move. Go to the north of the room and jump onto the adjacent roof.

Move up the wooden plank and take a left to descend the roof. Make your way from the edge of the roof until you reach another building with an open window. Crouch through it and make your way down the stairs. Metro Cops corner you from both the sides. You can try retrace your steps back up the ladder but to no avail. Inevitably, you will be trapped and knocked down by the Combine. Never fear, Alyx Vance comes to your rescue and shows the Combine a good time with the heel of her boot. Follow Alyx through the next section to get to Dr. Kleiner's Lab