Rewards: 1330 (+250), EXP: 600 (+250), Schematic: Devil's Handshake
Challenges: 1. Do not kill any policemen. 2. Do not damage the Gladstone's carriage.
Head to the Gladstone's house, then speak with the nearby kid in the open doorway and snatch the chest inside. Hijack a carriage and drive the the waypoint. Rope launch to the building on your side and approach the police officer stealthily from the back to strangle him. You can't kill any police officers in this area, so if you take any of them out, do so with knockouts only.
Scan the area, then rope launch to the building directly in front of you, on the far other side of the square. Below is a tent, under which the invitation you need to steal is lying. There are three police officers of interest here. The first patrols in a straight line underneath the tent. A second one is patrolling in a straight line past a stack of hay, and a third one is standing at the exit near the stack of hay. You'll first want to take out the one patrolling near the stack of hay. Jump on the tent, wait for the first officer to move back under the tent, the follow the one out in the open and strangle him near the stack of hay. While you're here, also strangle the officer on guard at the exit. You can now move closer to the third, last officer under the tent, by moving to the crates or barrels. With him out of the way, steal the invitation and exit the area.
Now for the second invitation. Head to the waypoint to reach the station. Mrs. Gladstone is sitting in the middle of the station. There are two ways to steal the invitation stealthly. The first is to rope launch to the bars at the top of the station, drop down behind Mrs. Gladstone and snatch the invitation. The second method is to wait for her to move to a dressing cabin a few meters away from where she's sitting. The cops will follow her and reposition, allowing you to stealthly approach the cabin, enter, and hug her, stealing the invitation. Exit the area, then drive the carriage VERY carefully to its destination - don't hit anything.