Lara has sneaked aboard a train hurtling across the Egyptian desert towards Alexandria...

Get used to the swaying motion and light a flare to check out the box car. There are two levers set into the floor but one has no handle. Pull the working lever to open the door at the back of the wagon. Head over to the doorway and take a slightly tricky standing jump to the balcony of the next coach (this isn't the movies - one slip when jumping between carriages and Lara will go under the wheels!)

Use [Action] to open the door and go in. This wagon has a corridor with three rooms leading off. You can open each door with [Action] and in the first two compartments you'll find breakable crates concealing a small medikit and shotgun shells. The breakable crate in the third compartment is empty, but before you discover that you'll come across the first of many assassins sent by Von Croy...

He appears as Lara approaches the third compartment. All these guys are the type that use their swords to shield themselves from your bullets - put away your guns to get them to drop their guard. When the first bad guy is down, head out to where he came from and jump to the flat wagon with the tarpaulin. Cross over this wagon towards the next, noting the two bad guys who board the train from moving trucks. When control returns from this sequence, take out the two newcomers.

Jump to the flat wagon and cross to the far side. Jump from the edge of the wagon to the ladder on the left side of the door on the next truck. Climb up to the roof. When you get beyond the skylight on this truck it opens, revealing another bad guy (and you may also have noticed another on the truck ahead). Take out at least one of these guys and drop through the first skylight into the truck below.

Explore the inside of the wagon carefully - there's another bad guy lurkinf in a dark corner. You'll also find shotgun shells and a breakable crate, which reveals more shells (you'll have to crouch to shoot it). Jump to catch the edge of the skylight and climb back onto the roof. Jump to the next wagon and go to the end of the roof.

The next wagon contains something tall covered in a tarpaulin - the sides are too high to climb, but you can jump to a flat spot near the corner of the wagon and then drop off the side to shimmy along the edge of the truck, with Lara's feet barely above the ground. Climb back onto the truck when you reach the far end (just in time to see Von Croy's helicopter dropping in reinforcements).

Jump to catch the ladder to the left side of the door on the last wagon. Climb up to the roof and start to cross it. An assassin will appear as you reach the middle. Kill him and head towards where he came from...

At the end of the train, turn around and drop off the roof of the wagon. Grab on to the edge of the roof and a door will open nearby. Line up at the entrance and then drop off the roof and immediately grab the edge of the doorway. Pull up and go in. This is Secret #1 - a large medikit, arrows and revolver ammo. Climb back to the entrance hole and drop off backwards, grabbing the edge. Shimmy right and climb up to the roof.

Drop off the right edge of the roof and shimmy to the right - there's another opening here which you have to crawl into after dropping and grabbing again. This time you get inside the main compartment of the wagon. Here there's two boxes of shells, the shotgun (more shells) and a crowbar. Use the crowbar to operate the broken lever set into the floor of the carriage (aha!) - which opens the door of the wagon and lets in another assassin.

Take care of the bad guy and then jump to the wagon with the high tarpaulin covered load. From this end you can get onto the top of the load and will see one of Von Croy's men approaching you from a long way away. It's best to meet him halfway, so slide down the load towards the closed door of the next wagon... Which opens, revealing another bad guy.

When the coast is clear, jump into the boxcar and pry open the darker coloured panel at the far right using the crowbar (use a flare to find the right panel). This is Secret #2 - the grenade gun and 2 boxes of flash grenades concealed inside breakable crates.

Climb up through the hatch in the roof and take out the baddie if you didn't earlier. Yet another assassin appears either here or when you jump to the roof of the next boxcar. Send him the way of his comrades and then continue forward to the empty flat wagon. You see yet more tropos arriving on a truck...

Kill the 2 baddies and jump to the wagon with the tarpaulin covering. Cross over it towards the wagon with the corridor and kill the final assassin. Go through this wagon and jump to the wagon that you started out in, using [Action] to lower Lara's arc a little. You've nearly made it now - just use the crowbar to prise open the wooden panel opposite the entrance and find Secret #3 - a small medikit.