Doctor Who (2005)

S05E11 The Lodger

On Aickman Road stands a peculiar house with a staircase that leads up but never returns down. To unravel the enigma of the mysterious lodger above, the Doctor must disguise himself as an ordinary person and move in with Craig Owens, sharing the flat. As he navigates the challenges of everyday life, he works to uncover the truth behind the strange happenings while maintaining his cover.