Noted playwright Williams, who chronicled the Moors Murders (Beyond Belief, 1968)--and who wrote his first novel (Headlong, 1980) at age 75--serves up a defense of the notorious wife-killer Hawley Harvey Crippen in the form of a diary supposedly sealed by Crippen shortly before his execution in 1910, and first published in Britain in 1987. Taking off from incontrovertible facts--there certainly was a woman buried in Crippen's cellar in Camden Town, and one of Crippen's pajama tops was buried with her--and difficulties with the customary beliefs about Crippin (would an intelligent medical man have openly bought a fatal amount of hyoscin from a well-known London pharmacist and administered it to his hated wife in his own house, knowing that he would thereupon be faced with the disposal of her body?), Williams offers a new explanation of Crippen's behavior: he had indeed planned to kill his wife en route to Dieppe, pushing her overboard and being rid of her forever; but before he had time to act, she accidentally took a fatal overdose of hyoscin, leaving him panicked, guilty, and unable to get up the nerve to report her death to the authorities. Williams' Crippen, a put-upon little man who has tolerated his wife's infidelities for years before quietly taking up with his secretary Ethel Le Neve (whom Williams exonerates completely in an Afterword), is forced into a spiral of increasingly desperate and contradictory stories about his wife's disappearance before he is finally brought down by his nemesis, Chief Inspector Dew. True-crime fans will find Crippen's fictitious diary fascinating. But Williams' hero is too colorless to give this book the wide readership of Beyond Belief.