Some inhabitants of a Welsh development harbor secrets. Drugs, illicit affairs, underage sexual encounters, and other dark habits haunt the people, many of whom are curious when a previously empty house shows signs of someone moving in.
New arrival Jan meets her neighbors at Jac's birthday bash. Drug-dealing Huw is sure Jan is there to spy on him. Jan also elicits interest from others in the close, while we see Gruff's Internet activity and the trouble it gets him in.
Huw's suspicion about Jan is confirmed as he searches her mainly empty house. Gruff believe Pat is behind the blackmail thanks to the nude photo he uploaded. Betti tries to get Jan and Ben together, but he has not been taking his meds.
A shocking death leaves the inhabitants stunned. We meet Ben's estranged wife who tangles with Beti. Jan's motive for her deception begins to become clear as well as the target of her activities.
Tensions at the New Year's party simmer as residents begin to suspect Jan is up to something. Linda gets an acting job, but Pat loses out on a part and her continued presence in Linda and Tony's home begins to grate on him.
Jan's motives become clear as she plots to destroy at least one life she's wormed her way into. But chaos ensues as Beti's delusion intensifies, Huw is forced by Caroline to help her brother, and Pat discovers Linda's affair with Roger.
Richard discovers Jan's identity but Jan uses his daughter to exact revenge on him. Linda finally leaves a bedridden Tony, much to Pat's dismay. Caroline's brother overstays his welcome and becomes embroiled in the drama of the close.
