You'll return to town and to start this next mission, you need to return to the inn and talk to your compatriots. After you talk to them, head back outside and talk to Charles to find the last man on your list. Lee will lead you to talk to General Braddock. Walk with Lee through the camp and you'll meet with General Braddock.
Unfortunately, the meeting doesn't go so well so you'll have to come up with another plan. Thankfully, they are leaving the camp so follow after them. You'll learn how to tail people and after giving Lee his instructions, climb up to the rooftops and follow after the troop. You need to keep them in sight or a timer will appear at the top of the screen, if this runs to zero before you see them again, you'll have to start over. Climbing to the rooftops will allow you to see them pretty easily while still maintain enough distance to not be noticed.
Follow them through Boston and you'll automatically yell to Lee to start his diversion. When he does so, follow after them and it will lead you to back alley area where a fight will ensue.
An important feature will be introduced here called "Snitches". Snitches are generally coward enemies or enemies without weapons (like the drummers) who flee rather than fight. If one of them manages to escape the battle and make it off of your compass, he'll summon more soldiers to the fight. You can pick a snitch out of a group almost instantly. Rather than simply have a red marker over their head, they will have a red marker surrounded by a white ring. Take these enemies out first to save yourself some trouble.
With the snitch out of the way, continue your fight until you've eliminated all of the enemies here. There is a second constraint where you need to get a three chain combo. To do this, you must first kill an enemy and immediately after killing him, push in the direction of another enemy and attack him. If you time it correctly, Haytham will move from one killing blow to the next and this can be chained indefinitely, allowing you to kill each enemy in a single strike. Manage to add two more enemies after your first to meet this constraint. Once you've eliminated everybody, talk to Braddock who is sitting on the floor.
You'll finish this mission and return to the inn.
