On this page of the Hitman 3 guide, you will find detailed information on how to get the Bullet Train trophy/achievement. This trophy is associated with the Carpathian Mountains (Romania) map. You can get it by eliminating three guards using three specific weapons with a silencer. It's important to note here that you can't take any weapons on the Untouchable mission – you'll have to get them as you explore the train.
Get out of bed and walk through the glass door. You will notice an employee in a white apron sitting at the desk - attack him from behind, make him lose consciousness and take his access card. Leave the room.
Further down the corridor, you will encounter two employees. Avoid them and go to the next room.
Approach the cold storage door and open it: code 1979. The same number appears on the poster to the left. In the cooler you will find a rusty crowbar - pick it up and return to the previous room. Use thecrowbar to open the large metal door. While holding onto the wall of the train car, move toward to the next one. When you reach the icy surface, climb to the roof.
A little further ahead you will encounter one opponent. Jump off the roof, approach the man from behind, and take him down. Change into his clothes and take the pistol. Go to the next train car.
Walk to the end of the train car and pick up a valve from the ground. Then go back to the beginning of the wagon and install the valve at the location shown in the image above. Turn the valve to open the hatch in the wagon roof.
Go outside and, keeping to the right, move forward. Enter the train car and continue forward - the sleeping guard won't pay attention to you unless you start generating noises.
The corridor of the next train car is patrolled by one guard. When he turns his back on you, go to the nearest open compartment on the left. Lock the door behind you for safety.
Wait for the guard to pass you, then go behind his back and reach the hallway with a door on the left. Go through the open wagon with the tree and enter the next wagon.
Approach the workbench and create a weapon with a silencer – you will need it for the Bullet Train trophy/achievement. Go to the next train car. If you have not yet unlocked the Passenger Cart Door shortcut, follow the instructions below.
Once the guard is not looking in your direction, go through the window on the left. Then go to the left and climb to the roof. Go to the right side and down to enter a small storage room through the window.
On the crates on the left, you will find two required weapons: a tactical shotgun and an SMG. Before you leave this room, make sure you have all three weapons on you - one weapon must be held in your hands and the other must be placed on your back.
There are three guards in the next compartment. Eliminate each of them using a different weapon.