Reverse Engineering

When Patricia is invited to a secretive Swedish clinic by an old colleague, she tips off the Doctor, Mel and Hebe, who go undercover to investigate. Charismatic geneticist Killian Holm offers to restore youth to his wealthy patients, but the truth of his work is far more radical - and far more dangerous!

As an ancient horror reforms beneath the clinic, the Doctor must race to save humanity from an unspeakable temporal disaster.