[1] In the episode, the alien-hunting team Torchwood seeks to shut down a pharmaceutical company that is experimenting on live aliens to develop a drug that restores the human body to its "factory settings".

Further investigation shows that the murder victims have previously suffered from incurable diseases such as diabetes and HIV, but were cured of them prior to their deaths.

Jack detects a strong presence of alien life forms within the Pharm, and the facility's security system proves to be beyond the ability of Torchwood to hack from the outside.

The director, Professor Aaron Copley, injects Martha with multiple doses of Reset, curious to determine the effect of Mayflies on her immune system, which has changed from travelling in time.

The team rush to the Pharm hidden in Billy's vehicle, using his corpse in the driver's seat to fool the security guards into letting them inside the compound.