Daniel and Clarisse are summering in Provincetown (he is tending bar and she working at a gift shop) when Clarisse discovers Jeff's body on a...

Daniel and Clarisse are summering in Provincetown (he is tending bar and she working at a gift shop) when Clarisse discovers Jeff's body on a beach. Cobalt is the color of Jeff's arresting eyes, and those eyes have made him both a lot of friends and quite a few enemies. Which of these killed him?