The prequel to the Doctor Who season premiere has a deceptively simple plot. The Doctor is consoled by a little girl, who unbeknownst to him is younger version of Clara Oswin Oswald the death-defying girl he’s been looking for. She intuitively realizes he’s lonely and asks “Have you lost something?” The Doctor says no but she tells him that when she loses something she goes to quiet place and closes her eyes to remember where she put it. One of the things she mentions losing is her gran as in grandmother or grandfather, which could be a hint that Clara is Susan, the Doctor’s granddaughter and first companion. Remembering has been an ongoing theme. Clara’s catchphrase is “Run you clever boy, and remember.” There is clearly some preexisting relationship between the Doctor and Clara. Two other possibilities are that Clara is River Song or the Twelfth Doctor.