Dust off the tinfoil hats: the 40-year-old USS Scorpion conspiracy theory has been revived.The Scorpion was a nuclear submarine launched in 1959 to play cat-and-mouse with the Soviets at the height of the Cold War. On May 22, 1968, as it was returning from a Mediterranean patrol, it sank - an accidental tragedy that claimed the lives of 99 men, and became the Naval equivalent of the Kennedy assassination.The latest manifesto is "All Hands Down: The True Story of the Soviet Attack on the USS Scorpion" (Simon & Schuster), by Kenneth Sewell and Jerome Preisler. This rumor-packed thriller, mostly devoid of named sources or documentation, claims a Soviet helicopter-launched torpedo took the sub, and the outrage was covered up by President Lyndon Johnson and Chief of Naval Operations Thomas Moorer."All Hands Down" is not the first book to posit this theory; alas, I fear it won't be the last. But my own research, as well as numerous inquiries, show that the Scorpion's sinking was purely accidental.Records have revealed that the Scorpion was an unhappy boat, and at least one officer, who perished on the Scorpion, railed against the elimination of safety work. The submarine force of the late 1960s struggled with intractable maintenance problems to meet the unending demands of Cold War missions. During its final mission, the Scorpion was bleeding hundreds of gallons of hydraulic oil as its crew inhaled Freon from faulty refrigeration systems.Located five months after it sank two miles below the mid-Atlantic, the Scorpion was found chopped into three main sections by implosion forces. Structural experts could find no sign of collision or attack damage. The nuclear reactor and two plutonium-tipped torpedoes remain 11,000 feet beneath the Atlantic.The deadly-accurate Soviet Navy described in "All Hands Down" bears little resemblance to the actual one that tried and failed to sink the Scorpion in 1966 when it was caught inside the USSR's White Sea spying on Soviet missile tests. This is the same Soviet Navy that bungled the search for its missing submarine K-129 in the Pacific two months before the Scorpion's disappearance.Unwilling to waste an unrelated dramatic event, "All Hands Down" makes the additional silly claim that the Soviet's sank the Scorpion after deciding America was responsible for the K-129's sinking.Light adventure reading has always taken liberties with the facts. Sadly, conspiracy books like "All Hands Down" manipulate grief into gold by trivializing the deaths of brave men.As the families of those who died aboard the Scorpion gather for the 40th memorial service at Naval Base Norfolk on May 24, the controversies - both real and imagined - will hover over the somber event like an unwelcome cloud.Stephen Johnson is the author of "Silent Steel: The Mysterious Death of the Nuclear Attack Sub USS Scorpion" ( Wiley & Sons).