Blue Octavo

Young bookseller John Cain has inherited stock from curmudgeonly dealer James Roach after he appears to have committed suicide. But Cain is unconvinced that Roach really died by his own hand, especially considering the alleged suicide followed the dead man's strange behavior at an auction where Roach had grossly overbid on a thin blue volume about mountain climbing. The book appeared to be as exciting as its title, 'Grey Boulders', but why had Roach been so obsessed with owning it and why is it now missing from Roach's collection?