Death to Spies: Moment of Truth/White Head

In White Head, you are sent to a residence to meet with a contact, and to assassinate a defecting courier and an officer meeting with him.

For this mission, you may want to add poison to your equipment before deploying.

Meet with the contact
Near one of the warehouses, there is a worker at one of the buildings. When you talk to him, he will give some information about some documents being mixed in the trash and are about to be burned. As a secondary objective, he will instruct you to retrieve the documents from the boiler room within the residence.

Recover the documents
Before advancing, you may want to get a disguise, and two are available. The first disguise is in the building next to the informant, and is on the lower shelf. The clothes of the french worker allows you roam freely outside (provided they don't see your large weapon).

The other disguise is in the north-east barn. A sniper is taking a nap, and will not detect you approaching when you knock him out. The soldier uniform allows you access to the residence.

With a disguise, head to the back of the residence, and enter the door. You only need to worry about two soldiers, one of which won't see you if he's at his post, and the other which only takes a brief look in the hallway. If they detect you, you can leave safely as long as you aren't spotted inside the boiler room.

Pick the lock to the boiler room, and enter. Pick up one of the boxes, and move them into the truck outside. Repeat for the other two boxes. Once the truck is loaded, you can enter and drive it to the drop off point to the south - even if your disguise doesn't match what it should be, the guards won't give too much trouble.

The truck is optional - if you want to attempt to complete the objectives while killing as few as possible, you can still carry the boxes on foot.

Kill Ivan Melnik
Ivan Melnik is the courier, and is probably going to leak information about contacts in France.

If you're using the french worker uniform, you will need to enter on the right-hand side of the residence. Wait for the soldier to move away from the door, and sneak in when they're past. You'll alert the cooks, but they're calmed once you cross the room, and enter the room past the kitchen.
 * Poisoning

This room has a German worker hammering the wall, but also has a second door at the back. When nobody is looking, you can pick the lock to this room, or wait for the server to unlock the door for you. In this storage room, you can get the server uniform, which gives you access to the first and second floors without problem.

Get the dish from the kitchen, and bring it to his room on the second floor. The officer will unlock the door for you, and you may enter. Drop the dish, and head to the wine bottle near the window. Add the poison, and Ivan will die the next time he visits the room.

The room also contains a free officer uniform.

Ivan will occasionally visit the first floor, and sit on the furniture. Hanging above him is a chandelier.
 * Chandelier

On the corner of the second floor, you can cut the rope to have it crash down. If this is too suspicious, you can instead use a pistol to shoot the rope. If Ivan is sitting on the couch, he will get killed by the chandelier as it falls.

This method is generally risky, as this section is well observed.

Sniping the target is possible, but only saboteur difficulty provides you with a silenced sniper rifle.
 * Sniping

Kill Gerd Ricter
Ricter is a high ranking officer that is in contact with the courier. He has a bodyguard as well, who will follow him as he performs his tasks.

Head to the attic. You can approach it from the stairwell on the second floor. You will need to have the guard enter the main room before ascending the final flight of stairs. The attic contains a water valve which may be closed, cutting off the water supply to the bathroom.
 * Water supply

When Ricter next uses the bathroom and attempts to use the sink, his escort will enter the attic. If the escort is killed, Ricter will also enter the attic to see what's going on. He may be killed here, as nobody else will enter the attic.

On the third floor, there is a small office to the right of the main room. Pick the lock and enter. You can either attract the office worker here, or wait for him to approach normally. Knock out the office worker and take his uniform.
 * Poisoning

With that uniform, you can enter the north-west room, and poison the wine bottle. As long as you don't linger in this room, you won't be attacked.

Ricter will occasionally use the bathroom on the third floor. You can hide behind the screen and wait for him to enter, and kill him as he uses the sink. Hide the body behind the screen.
 * Bathroom attack

Other points of interest
The third floor has two secret passages that lead to the side rooms. While the rooms in question might not be restricted or simply provide demands to leave, the secret doors themselves may trigger combat if you pass through them. This may be either a glitch or an incorrect uniform.

On the third floor, the western room contains a projector. If turned on, you can attract most of the officers on the third floor into this room.

Saboteur difficulty
On saboteur difficulty, you can choose a silenced sniper rifle in your starting equipment. One of the barns in the map faces the front of the mansion, where you can snipe Ivan Melnik when he's visible in the left window of his room. It is recommended to do this task last, as there is a chance of causing an alarm (causing enemies to become alert.)

You may need to deliver the documents by carrying them by hand, as the few workers at the back door will not leave their position. It is difficult to eliminate all three of them without causing some alert, but if you do, you can hide the bodies either on the inside at the stairwell or behind the cabin that's behind the residence.

If you choose to use the truck, there is a chance of causing alarm but the guards will only engage if they see you are driving the truck. Once you're past the mansion, there's only a small number of enemy soldiers to worry about, where the minimap shows their fields of view.

It may be easiest to kill Gerd Ricter by luring him to the attic by cutting off the water.