On her way to visit her grandfather Vic at a retirement home, a young mother named Leanne disappears while buying flowers from a van parked off a highway, leaving her young son and daughter alone. By the time police have been notified, the two children have also disappeared, triggering a desperate search led by Detective Iain Barclay and his sergeant, Amy Foster.
Press officer "Tops" Topcu organizes a press conference -- where Matt learns his missing wife is pregnant. Meanwhile, Hazel suspects her son Kyle may have been involved in the abduction. Another major breakthrough occurs when the flower seller is located, and when a young reporter named Josh Fairley gets Vic to give him the key to a trailer he owns.
In the wake of a 28-day police review, Barclay has turned Leanne's disappearance into a murder investigation -- and Kyle Betts is the prime suspect. Matt and Farnes make a disquieting discovery: days before Leanne disappeared, she bought a one-way flight to France, where her ex-husband, Daf Parry, lives. Meanwhile, a body surfaces, raising fears for Leanne's family.
As the investigation drags on, Matt finds himself in a riff with Leanne's parents after he gives a TV interview. Later, as Tanya accompanies her father to the mall, hoping to travel with him to Paris, Matt and Sarah spend the afternoon at a local fair and road race in a park, which ends with a grisly discovery that takes the family on yet another emotional ride.
The discovery of a burnt-out van offers fresh evidence to Barclay's team, but the prime suspect slips away. As a furious Matt joins Gary (and the police) in a nighttime stakeout, Amy celebrates her retirement with a farewell party. But Amy's work on the case isn't quite finished -- several new clues bring her and Barclay to the verge of finally solving the case.