The fourteenth Doctor is living with Donna Noble and her family, he’s retiring, resting, while his other self — the newly bi-generated Fifteenth Doctor — goes off to continue the legacy. One day, when walking the streets of London with Donna, helping her carry things for Rose’s (Donna’s daughter , rose) birthday party, through the crowd of people he notices two eyes that look identical to His Rose, his rose from all those years ago, that’s now stuck in parallel universe. And as he’s processing the information with his signature “what?!” (And of course Donna has failed to notice, her back turned as she complains about one of roses “friends”.) people pass again, blocking his view, he sees her again, her lips set in a straight line, she’s fiddling with a camera, replacing something in the back.