Death on a Small, Dark Lake

Win Szczedziwoj, a man known for photographing subjects in the rain, is on a vacation. Just him, his camera, his canoe, and a small, dark lake well away from civilization.
That solitude comes to an end when his fishing line drags up a body from the lake. It looks like the usual canoeing accident, but the police suspect murder, and Win is suspect number one (I mean, what are the chances of actually snagging a body with a fishing line?)
But Win wants to know why the dead guy was hired as a guid...