This mystery can be found in the north of Lincolnscire, just south of Grimsby in AC Valhalla.
Read the Note and Carry the Man Back to Grimsby
When you arrive at the scene you’ll find a Norse Man sleeping on the ground beneath a large tree. Interact with the body to acquire a note, which you can then read from the Quest Items section of you inventory. The note indicates that the man has narcolepsy, and is therefore prone to falling asleep at any time. You can choose to kill the man if you want to end the mystery then and there, but we don’t recommend this. Instead, you can pick him up and carry him back to his wife in Grimsby, a small settlement to the north.
As you arrive in Grimsby you’ll hear the man’s wife shouting for him. Take him into the house and place him on the floor, then speak with the woman to complete the mystery.