The episode's cold open depicts a teenage vampire, Adam (Craig Roberts), being fed blood by his own (human) parents during the 1970s. In the present, Adam (still physically and emotionally a teenager, although now 46 years old) and his ailing, elderly father are admitted to Nina's hospital. Realizing the teenager poses a threat to the community, they track him down and bring him home for Mitchell to deal with. Mitchell, meanwhile, is contacted by Richard Hargreaves (Mark Lewis Jones), a representative of the "Old Ones" (ancient vampires living in peace in South America). With the police looking for Mitchell after the Box Tunnel murders, Hargreaves offers to get Mitchell out of the country. Hargreaves and his wife (Melanie Walters) offer to take Adam in, and Mitchell agrees. George and Nina aren't so sure that the Hargreaves are offering the wholesome home environment Adam needs, and they investigate—leading to a confrontation with the Hargreaves and their secret, kinky lifestyle. The episode concludes with someone inside the hospital's locked mortuary attempting to get out.