In South London a young man, Abdullah Asif, is shot dead delivering a pizza. The detective in charge, DI Kip Glaspie, quickly discovers that the pizza manager Laurie Stone, inexplicably sent Syrian refugee Abdullah instead of regular driver Mikey Gowans. At the crime scene, Kip dismisses pushy reporter Robert Walsh, and is briefed by her partner DS Nathan Bilk.

Bereaved sisters Mona and Fatima are processed at Harsfleet detention centre. Sandrine returns to her army desk job, under the threatening gaze of Major Dyson, and works through her troubled past in Afghanistan with therapist Xan.

Sandrine is increasingly fraught. Peter Westbourne tracks her down, but fails to calm her. Sandrine returns to the army base, retrieves herballoon and disappears. Faced with a second cuddle, Kip and Nathan struggle to figure out how the two huggings are connected. Kip is convinced that MI5 is leaking information to the media.

As the net draws in, DI Kip Glaspie enters a dangerous power play with MI5. But is it too late to save everyone involved?