"I'm your new undercover agent, on loan from Scotland yard. Code name, the Doctor. These are my top operatives - the Legs, the Nose, and Mrs. Robinson.
This is from the episode, The Impossible Astronaut and is postmarked on October 5, 2015.
The sender writes: Happy International (Intergalactic) Postcard Week!
Chuk Iwuji – Carl
Stuart Milligan – President Richard Nixon
Mark Griffin – Phil
Mark Sheppard – Canton Everett Delaware III
Matt Smith (Eleventh Doctor)
Karen Gillan (Amy Pond)
Arthur Darvill (Rory Williams)
Alex Kingston (River Song)