The Lodger

The Lodger is the eleventh episode of Series 5.

Synopsis
The Doctor forgets to set the TARDIS controls leaving Amy trapped inside as she ends up travelling one week into the future, without the Doctor. This leaves the Doctor trapped on Earth as he awaits the return of his TARDIS. While the Doctor waits, he discovers there's a house on Aickman road with a staircase that people go up, but never down... To solve the mystery of the man upstairs, the Doctor must pass himself off as a normal human being, and share a flat with Craig Owens.

Plot
Craig's flat has a staircase people go up but never come down. He is hiding his love for his friend Sophie when the Doctor turns up with a bag of rent. How did he now the address? Who is he? What is his name? This is what Craig wants to find out.