Pulitzer Prize--winning author Massie, whose 1967 Nicholas and Alexandra received high praise, has used new documents on the assassination of the Romanovs to write a sequel that is almost as much thriller as historical account. Beginning with the assassination in the basement of the house in which the royal family had been imprisoned in Ekaterinburg, Massie traces the early, covert efforts, mainly by geologist Alexander Avdonin, to find the bodies. In 1979, Avdonin and Moscow television producer Geli Ryabov used an account of the execution given them by the son of the executioner to find the grave site and exhumed the bodies. In 1989, news of this discovery set off a scramble among the local authorities, Moscow, and competing groups of forensic analysts in the West to study the remains of the Romanovs. These efforts led to the identification of the bodies of Tsarina Alexandra and three of the four daughters, with disagreement as to whether Marie or Anastasia was the missing daughter. The identity of the tsar himself was complicated by an unusual genetic anomaly that could have been caused by contamination. The results were also contested by â€šmigrâ€š groups abroad, who suspected a KGB hoax, and were entangled by disputes as to the missing members of the family. One of the most fascinating parts of Massie's story is his account of the controversy surrounding ""Anna Anderson,"" acknowledged by many of the Romanovs as Anastasia, but proved in recent DNA testing to have been ""an impostor with astonishing physical similarities"" to the dead princess. Finally, Massie deals with the bitter squabble among surviving members of the family about ""who is and is not qualified to claim a nonexistent throne."" (For more on the assassination, see Mark D. Steinberg and Vladimir M. Khrustalâ€°v, The Fall of the Romanovs, p. 1264.) With memorable sketches of the main participants and a skillful discussion of the scientific evidence, Massie pulls together a sprawling theme and infuses it with quiet drama.