From the start, drop down into the haycart. Make your way over to the right. You will find a fence. Either hop over it or go around it. You want to make your way toward the spectator box that you can see.
On the other side of the fence, carefully make your way to the hay cart. Watch the nearby Soldiers that are patrolling. There are a few gaps in their routes. Use these options to slip back toward the carriage you can see behind the observation area. Use Eagle Vision as you get close. You will find Germain right there in the back. Slip up toward him to trigger a cinematic.