The British brig Dei Gratia was about 400 miles east of the Azores on December 5, 1872, when crew members spotted a ship adrift in the choppy seas. Capt. David Morehouse was taken aback to discover that the unguided vessel was the Mary Celeste, which had left New York City eight days before him and should have already arrived in Genoa, Italy. He changed course to offer help. Morehouse sent a boarding party to the ship. Belowdecks, the ship's charts had been tossed about, and the crewmen's belongings were still in their quarters. The ship's only lifeboat was missing, and one of its two pumps had been disassembled. Three and a half feet of water was sloshing in the ship's bottom, though the cargo of 1,701 barrels of industrial alcohol was largely intact. There was a six-month supply of food and water—but not a soul to consume it Thus was born one of the most durable mysteries in nautical history: What happened to the ten people who had sailed aboard the Mary Celeste? Through the decades, a lack of hard facts has only spurred speculation as to what might have taken place. Theories have ranged from mutiny to pirates to sea monsters to killer waterspouts. Arthur Conan Doyle's 1884 short story based on the case posited a capture by a vengeful ex-slave, a 1935 movie featured Bela Lugosi as a homicidal sailor. Now, a new investigation, drawing on modern maritime technology and newly discovered documents, has pieced together the most likely scenario.