"Laid to Rest" is a mission in Sequence 12. Be sure that you have the Poison Darts as it will ensure success here.
Optional Objectives
Limit Regular kills: 15
Kill the HMS Jersey Captain
Escape the HMS Jersey without entering Open Conflict
Walkthrough
Head straight on forward to the service that is going on. Connor is taken in a cutscene and shown to the person he is after: Charles Lee.
Objectives
Climb the HMS Jersey undetected