2197

On 16 January 2197, the Sixth Doctor and Evelyn Smythe materialised on Valiant. They found some of its crewmembers were hearing a mysterious bell, just as they had in the TARDIS. They quickly ran afoul of Captain Oswin while trying to investigate the incongruous sound.

The Doctor and Evelyn soon discovered the ship had a mysterious, ancient door in its cargo hold. It led into open space. The bell seemed to be a kind of "siren call" which led crewmembers who heard it through the door and to their deaths.

Realising the grave danger this door posed, Captain Oswin sent a distress call to Earth, but did not hope that backup would arrive any sooner than about two months. (BFA: The Nowhere Place)