Sometimes you regret the impulse, and other times, as with my recent reading of David Vann's recent novel Caribou Island, you are very, very grateful. [We are showing the UK cover on the right, which is the one Jeff picked up, and we think is the more attractive one. --Ed.]Vann chronicles the darkly decaying marriage of Gary and Irene in a remote Alaskan town in a way that conjures up echoes of Corm