Captain Jack calls in Martha Jones, now working for UNIT, to assist the team in investigating a string of mysterious deaths. However, when the trail leads to a medical testing centre, The Pharm, Martha puts her life on the line to go undercover in the increasingly sinister pharmaceutical facility.

Benched from the team and feeling increasingly victim to his newfound circumstances, Dr. Owen Harper struggles to find his place in the world. Will the lonely girl on the rooftop help him, or will it be a mission to retrieve an alien device that is proving more lethal by the second?