Doctor Who episode Rosa introduces us to the villainous Krasko (Joshua Bowman), who the Doctor immediately recognises from the identifier on his wrist as a former inmate at a prison called Stormcage – “the most secure facility this side of the universe”– where he served (presumably quite a lot of) time for the murders of 2,000 people.
But this is not the first time we’ve heard of Stormcage – or the first time we’ve met one of its ex-convicts…
Stormcage Containment Facility is the maximum security prison in which River Song was sentenced to 12,000 consecutive life sentences for the murder of the Doctor.
It’s located on an unknown planet where an unending storm rages and according to various Doctor Who sources from outside the TV series itself, security measures include regular patrols of armed guards, security scanners equipped with facial recognition and a Tesla binding field designed to stop inmates escaping using time travelling devices like vortex manipulators.
Nevertheless, River managed to escape multiple times, including to warn the Doctor about the Pandorica opening, to meet him near Lake Silencio and to go ice skating with him on the frozen River Thames for her birthday during a trip to 19th century London. She always returned to Stormcage, coming and go pretty much as she pleased until her eventual pardon.
Interestingly, there’s a suggestion that Krasko and River may have met during their time in Stormcage. Read more about that here.