Sheriff's deputy Katarina Brown was just starting to examine the bone in the sinkhole when she looked down at the shifting earth under her feet. She was standing inches from an eerie set of white teeth. It was a skull - make that two skulls, complete with jawbones and eye sockets. Bending closer, she could see each skull had a hole the size of a quarter in the back of the cranium. These didn't look like old bones."Don," she yelled to archaeologist Donald Mosier, who was standing on the rim. "You'd better have another look at this."Human remains have been turning up on Whidbey Island for decades. The island's largest community, Oak Harbor, sits partly on the site of a Native American burial ground and longhouse settlement going back thousands of years. When bones began turning up during a street project in Oak Harbor's Old Town in 2011, they brought work to a halt. These bones were different, and Brown was determined to know whose they were, and how they got here.