Friends In High Places

When Casey met the Doctor, she thought she'd seen it all. But, one day, their travels take them to 221B Baker Street. It was there that they met Sherlock Holmes and John Watson. And, later, they bump into the Winchesters, who were there working on a possible case. Coincidence? Probably not. But the real mystery at hand is Ms. Casey Logan, who is hiding more then even she realizes.