One day, while off home sick from school, Ana had found a package labelled "DO NOT OPEN 'TIL XMAS" delivered to her door. She brought it inside. Mason and a shrunken Tenth Doctor, who sat on Mason's shoulder, arrived to investigate; the Doctor having arrived in a similar package with no memory of how he got inside.
The Doctor found an Ulian robot inside and prematurely activated it. The robot attacked, mistakenly transmatting Ana on board its ship. Ana was placed in a cell behind electric bars and was dressed as the Ulian Princess Cilia. The Doctor released Ana from her cell. The Doctor had remembered why he was in the box: he had been searching for the missing princess and upon discovering her ship, the robots attacked, unwittingly shrinking him and placing him inside one of the packages, which the robots had been using to find Princess Cilia, whom they only knew was somewhere near a Christmas tree. The Doctor told the robots that Ana wasn't the princess, and though their methods of tracking the princess were scrambled, he could find her easily. The Doctor was brought back to full size and returned Mason and Ana to Earth in the TARDIS. The Doctor discovered Cilia in one house disguised as a fairy on a Christmas tree. Ana told Cilia the war was over, and the Doctor told her to order the robots to send her back to Ulian Alpha.
When Ana was sceptical of the Doctor being a sort of Father Christmas, the Doctor pulled a box of "Swiss Miss Hot Chocolate" as an early Christmas present. Ana excitedly ran off with her gift to make some hot chocolate. (PROSE: The Doctor on My Shoulder)