The letter was for Dr. John Smith. No address was listed because the Doctor hadn’t given her one. Lauren didn’t write her last name or return address on the envelope either; she knew he’d be difficult to find and didn’t want it returned prematurely.
Eventually it was delivered into the hands of two very perplexed women living in a house on Baker Street.
“A letter.” Molly took it from Liv. “Don’t they have those in the future? We’ll give it to the Doctor later.”
“If he comes back.”
“He will.” Molly smiled. “Like a bad penny, that one.”