Shelly's husband Jason, a Garda Detective, is delighted to be assigned to the case, with no sense where the trail may lead. While he and his co-worker, Fiona, focus on a sex worker, Shelly realizes she may have left evidence in the dead man's hotel room.

We learn of Shelly's dark history, as a teenager who was part of a drug ring in London 20 years earlier with Charlie Lynch, the man she shot.  When Lynch's true identity is uncovered, a UK officer, DSI Crichett, reopens an old murder case Shelly and Charlie were linked to.

The investigation continues to build steam in both countries, while Shelly continues to juggle her parenting and family responsibilities – problems with her husband and children that would stress anyone.  As Jason's partner Fiona grows suspicious of Shelly, we learn of the measures Shelly took to change her identity.