Well that must have been weird: A marine robot scouring Loch Ness in Scotland detected something at the bottom of the lake, something that looked exactly the Loch Ness Monster. And it was indeed Nessie. Except, as Reuters reports, it was a long-lost 30-foot replica built for a 1970 Sherlock Holmes movie that sank during filming. "We have found a monster, but not the one many people might have expected," Nessie expert Adrian Shine tells the BBC. There's still hope for believers, though: The underwater robot from Norwegian company Kongsberg Maritime isn't finished mapping the lake, a project called Operation Groundtruth that will result in the first high-resolution survey of the body of water, reports Discovery. It should wrap up next week.