An American father and son set off into the tangled unknown of the Brazilian interior. But not just any father and son. At the centre of this steamy slice of gothic fiction are former US president Theodore Roosevelt and his son Kermit. They really did travel down a remote Amazon tributary in 1914 on an ill-advised expedition that left 19 people dead, Roosevelt senior's health devastated, and Kermit an alcoholic, malarial mess. Bayard turns this extreme adventure into an elegant page-turner. Part mystery (the eponymous beast, which disembowels its victims but leaves no tracks), part warts-and-all exploration diary, part meditation on the debilitating effects of depression, it's beautifully written and, despite its heart of darkness, great fun.