By L.S. Klepp
Updated October 13, 1999 at 04:00 AM EDT

Hitler and his niece, Angelika ”Geli” Raubal, were living in the same Munich house when she was killed by a bullet fired from his pistol in September 1931. Geli, a lively, witty young woman, was no Nazi and had been restive under Hitler’s increasingly domineering obsession with her. After her death, ruled a suicide, he said she had been the only woman he would ever love.

Was there a sexual relationship? Was Geli actually murdered because the affair, if made public, would have derailed his rise to power? In Hitler’s Niece, a fact-based novel, Hansen’s attempt to solve the mystery approaches melodrama. But the incidental detail accumulates into a brilliant, chilling account of the way psychological deformity and historical chance propelled Hitler and his confederates toward triumph.