As the Torchwood team is reunited, Jack realises he's the most vulnerable man on Earth; and a flight to the USA turns into a desperate battle for survival.

One day, nobody dies. All across the world, nobody dies. And then the next day, and the next, and the next, people keep ageing – they get hurt and sick, but they never die. The result: a population boom, overnight.

With all the extra people, resources are finite. It’s said that in four month's time, the human race will cease to be viable. But this can’t be a natural event – someone’s got to be behind it. It’s a race against time as CIA agent Rex Matheson investigates a global conspiracy. The answers lie within an old, secret British institute. As Rex keeps asking: "What is Torchwood?", he’s drawn into a world of adventure, and a threat to change what it means to be human ... for ever.

In the launch episode of Torchwood: Miracle Day, Agent Rex Matheson is impaled in a car crash and miraculously survives, while his analyst, Esther Drummond, sets out to discover what Torchwood is. Far away, in Wales, Gwen Cooper lives in hiding with her husband Rhys and daughter Anwen – she’s the last surviving Torchwood member and is determined to stay hidden. In Kentucky, convicted murderer Oswald Danes survives his own execution. And when Esther meets the mysterious Captain Jack Harkness, assassins are activated to kill them all...