Patrick Mulkern from the Radio Times said: We sat pinned to our seats for 90 minutes or so of electrifying, bamboozling television, which might just be also the most unsettling since the series came back in 2005. I certainly don't think my nearly-four-year-old niece, who's obsessed with Amy Pond but still creeped out by last year's relatively tame Prisoner Zero, will last long into episode one before quailing behind a cushion. ... The chills are leavened with laughs (the Doctor flits through history, upstages a timeless comedy duo, and dubs his chums "the Legs, the Nose and Mrs Robinson"). River makes two spectacular entrances. There's a new use for dwarf star alloy (conceived 30 years ago in Warriors' Gate, it enchained one of The Family of Blood in 2007). And the number 1,103 may be significant. Moffat ladles mystery upon mystery, so that by the end we're gagging for answers. The second instalment concludes with a mouthwatering cliffhanger.