BRIEFLY NOTED.

Restless, by William Boyd (Bloomsbury; $24.95). Boyd's ninth novel, an absorbing historical thriller, is loosely based on the history of a covert branch of British intelligence created to coax America into the Second World War. The story unfolds on parallel tracks as Sally Gilmartin, born Eva Delectorskaya, a Russian emigree recruited into the British Secret Service in 1939, reveals her clandestine past in an autobiography that she gives to her daughter, Ruth, a graduate student and single mother living a dull civilian life in Oxford in 1976. These installments give the narrative momentum (the accounts of Ruth's daily life drag, by contrast) as Eva describes the taciturn spy who recruited and trained her before becoming her lover; her secret propaganda work in New York; and the act of duplicity, almost deadly, that forced her to flee to England and live under an assumed identity. Ruth barely has time to process the shock of her mother's secret before she is swept into a dangerous game: finding her mother's betrayer before it's too late.

Ancestor Stones, by Aminatta Forna (Atlantic Monthly; $24). Forna's first book was an unflinching account of her childhood in Sierra Leone and her investigation into the death of her dissident father. Here, in her debut novel, the setting is an unnamed African country that passes, in a single generation, from village life--"an order in which everybody had their place"--to colonialism and civil war. The story is told in the voices of four women, daughters of different wives of the same father. More archetypes than characters, they come to life only in flashes of color: one is schooled by nuns, her baptism paid for by the "Pagan-Baby Project"; another grows fascinated with the colonials' skin, which "tore like old cotton." Forna's strength is in invoking the menace in daily life under a corrupt regime. On election day, people are so frightened by soldiers that no one walks the streets except the lunatics, ...