Suzy's a British soldier, born and bred, but fitting back into civilian life after fighting in Iraq isn't easy. Haunted by the responsibility she feels for the death of an Iraqi child, she becomes obsessed with the safety of her own daughter, feeling the need to protect her against a threat that doesn't seem to exist. As Suzy's paranoia builds, her behaviour becomes more and more erratic, until finally, she puts her own child in serious danger.

After the mobster who murdered his partner is acquitted, semicorrupt detective Robert Bryant hires a beautiful female assassin, Maria, to kill him. When he discovers that he cannot afford Maria's services, Bryant is forced to hire another assassin, Madison, to kill her. Maria survives the doublecross and sets out to collect what's owed to her, one way or another.

Set during the 1960s in the fictional North Yorkshire village of Aidensfield, this enduringly popular series interweaves crime and medical storylines.