Handshake wants you to work with wealthier clients in Gray Zone Warfare. While these clients may be different from your typical choices, they pay well. For The Man Who Disappeared, Handshake wants you to leave a passport in a filing cabinet.
The Man Who Disappeared | Handshake | Gray Zone Warfare GUIDE | Fast/Solo | Mission Tutorial
It may seem like a simple task for Handshake, but this task is anything but easy. You should expect to be entering a heavily guarded location in GZW, and you'll want to bring enough ammo to ensure you can take out the huge number of NPCs guarding the location.
The location you need to visit to deliver the passport to the filing cabinet is the hotel in the center of Midnight Sapphire. You can find this location on the north side of the map and it is heavily guarded in GZW. Many NPCs have heavy armor and powerful weapons that they are ready to use against you.
When you accept the mission from Handshake, make sure to grab the passport from the command center in your base camp. You should find it on the table next to the many chairs. You need to hold this item to complete the mission. Also, if you ever die during this mission in Gray Zone Warfare, you will lose your passport and will have to accept the mission from Handshake again. You should keep this in mind if you ever die multiple times. You will lose the passport every time, regardless of whether you leave it in your SafeLock inventory slot.