Prison guard (The Impossible Astronaut)

The Prison Guard was a human guard at the Stormcage Containment Facility. He reported that River Song was packing her belongings (again) after she received the TARDIS blue invitation sent by the Eleventh Doctor. When asked why River was packing, he informed the person on the other end of the line that River said she was going to "some planet called America". (DW: The Impossible Astronaut)