Justin Curtis (John Hopkins) has shot a PC who wanted to arrest him for the hit and run of Audrey Byrne (Dorothy Duff). Curtis claims he has been set up by ‘Smith’, a sadistic identity thief intent on destroying his life. The Identity Unit prove that Curtis couldn’t have committed the crime. The team go back over all the cases of wholesale identity fraud over the last few years and two more similar cases emerge. Bloom (Aidan Gillen) is convinced that ‘Smith’ is punishing his victims for playing away from home. Bloom knows that Curtis has a secret life – as soon as Bloom persuades him to spill, he uncovers the real identity of ‘Smith’. Martha (Keeley Hawes) and Bloom have him in their sights – will they catch him or will he outwit them once more?