There are fairies at the bottom of the garden. But forget any ideas about little people with gossamer wings and a sunny disposition. These are the real fairies, the cruel, murderous, dark beings from the dawn of time.

The fairies will do anything to protect their “chosen one” – a child they want to take away to become one of them, for they were all once children, taken over millennia, and now they are immortal beings with power over the elements.

In this episode, written by Sapphire and Steel creator P J Hammond, it all gets a bit personal. The fairies kill an elderly woman whom Jack knew and loved during World War II[1]. They lost touch back then, Jack found her again, telling her that he was the son of the man she knew. And Gwen gets a nasty shock when they trash her home, leaving their trademark red flower petals behind them. Jack’s seen the petals before – back in 1909, he was in command of fifteen soldiers on a troop train, who all died horribly. It seems there is a lot more of Jack’s history to learn.

And while we’ve seen Jack at his most vulnerable, in the end he has to make a decision, and does what he has to in order to save the Earth. The rest of the Torchwood team aren’t happy with his actions, but Jack couldn’t see any other option.

The story had something in common with Sapphire and Steel. The idea of forces from out of time having a devastating effect on ordinary people, and being opposed by “agents” who are more than a little mysterious, is quite familiar. And it’s a theme that works well for Torchwood, and goes a long way toward explaining why Hammond was recruited.

Oh, and you’ll never look at the Cottingley Fairies the same way again…

[1] Doctor Who viewers will recall that we first met Jack back then. And he’s still wearing the same coat, or at least a remarkably similar one.