Thirty feet (9.14 m) under the surface of the cold, murky Baltic Sea, Brendan Foley spotted something unusual in the wreckage of an ancient ship. Foley, AG95, a marine archaeologist and researcher at Lund University in Sweden, was clearing mud away from a wooden tankard wedged beneath a tangle of firewood when the tankard began to move on its own, pulling free of the sediment and rising quickly toward the surface. "I hadn't seen an artifact try to escape before," Foley said. "I had to hold it down." He flipped the tankard over, releasing bubbles of gas that had been trapped inside—remnants from the decomposition of the beer or mead it was holding more than 500 years ago, when the
