When Clara’s not on her intergalactic travels with the Doctor, she enjoys her teaching job at Coal Hill School, where she recently got friendly with maths teacher, Danny Pink, a former soldier. Danny and Clara’s first date is a disaster, and a series of misunderstandings end in an argument, with Clara storming off!

But she doesn’t have time to wallow, as the Doctor needs Clara’s help to seek out a nightmarish monster he’s certain has been silently following him for centuries. Yet when he hands over control of the TARDIS to lovesick Clara, they end up accidentally exploring Danny’s past and distant future!

As the Doctor and Clara flit across time and space, they cross paths with both Danny’s younger self and Colonel Orson Pink – an astronaut from 100 years in the future and a descendant of Danny’s! Will these encounters help the Doctor understand the monster that haunts him in the dead of night?

And can Clara salvage her romance with Danny?