The Torchwood team and Martha face danger at CERN in this special BBC radio episode, starring John Barrowman, Eve Myles, Gareth David-Lloyd and Freema Agyeman. Following the tragic deaths of two of their colleagues, only Captain Jack Harkness, Gwen Cooper and Ianto Jones remain of Torchwood, protecting humanity against the unknown. Martha Jones, ex-time traveler and now working as a doctor for UNIT, has been called to CERN -- the world's largest particle physics laboratory. They're about to activate the Large Hadron Collider, designed to recreate conditions after the Big Bang and thus give an insight into what the Universe is made of. But so much could go wrong: it could open a gateway to a parallel dimension, or even create a black hole. Voices from the past are calling out to people from the LHC, and scientists have started to disappear. Where have they gone? What is lurking in the underground tunnel -- and do the dead ever really stay dead?...

Saving the planet, watching over the Rift, preparing the human race for the twenty-first century... Torchwood has been keeping Cardiff safe since the late 1800s. Small teams of heroes, working 24/7, encountering and containing the alien, the bizarre, and the inexplicable. But Torchwood do not always see the effects of their actions. What links the Rules and Regulations for replacing a Torchwood leader to the destruction of a shopping center? How does a witness to an alien's reprisals against Torchwood become caught up in a night of terror in a university library? And why should Gwen and Ianto's actions at a local publisher have a cost for Torchwood more than half-a-century earlier? For Torchwood, the past will always catch up with them. And sometimes the future will catch up with the past......