The Torchwood team goes out for a drink, leaving Ianto Jones (Gareth David-Lloyd) behind. He secretly brings Japanese Cybernetics Expert Doctor Tanizaki (Togo Igawa) into the deep basement, where Ianto’s girlfriend Lisa Hallett (Caroline Chikezie) resides. She and Ianto formerly worked at Torchwood London, which was overrun with Cybermen. She was partly converted, and he wants to reverse the process. Tanizaki is able to make her breathe again on her own, but she tries to upgrade him, and he dies.

The rest of Torchwood return because of a rogue UFO. A power flicker in the Hub sends Ianto into the basement and he finds Tanizaki’s body. He is trying to hide the body when Lisa enters the conversion unit, draining even more power. Captain Jack (John Barrowman) thinks the Hub is under attack and sends Gwen (Eve Myles) and Owen (Burn Gorman) to the basement. Jack runs down to find Owen missing and Gwen about to be converted. He tries to shoot Lisa, but Ianto stops him and Lisa escapes.

Ianto approaches Lisa and is knocked unconscious. Jack sends Toshiko (Naoko Mori) to repower the emergency cells by allowing himself to be electrocuted. He survives, of course. He has the Hub’s pterodactyl attack Lisa, and Ianto punches him. A pizza delivery girl (Bethan Walker) enters the Hub and finds Lisa seriously injured. Jack threatens Ianto: kill her or he will kill both of them.

Toshiko finds Owen tied up and gagged. Ianto finds Lisa dead, but Lisa has implanted her brain into the hapless delivery girl. Lisa says she did it for her and Ianto and they can be upgraded into Cybermen together. The rest of the team arrive and open fire, killing both Lisa and the delivery girl.

The episode was basically a sequel to the Army of Ghosts and Doomsday episodes of Doctor Who, in which Tenth Doctor David Tennant defeats the Cybermen who destroyed the London branch of Torchwood. Until this point, Ianto had been something of a background character. The pterodactyl is named Myfanwy. True to the character of the Torchwood series, Lisa is about the only sexy Cyberman ever seen, worthy of a science-fiction paperback cover. The costume was not easy to get into, wear, or get out of. Not surprisingly, the episode was controversial among fans and critics. The original title—The Trouble with Lisa—was dropped as not very dramatic. Gareth David-Lloyd is rather brilliant in this, but Jack comes off as pretty heartless. When you’ve died a thousand times, I suppose you can get a bit blasé about death. One online critic said, I wanted to punch him out myself, and another replied: Look at some more episodes; you’ll feel that way again.