Psychologist Samantha Gerson comes to UCOS to carry out a work study on older men. However she also wants the team to look into a suspicious hit and run from six years earlier, the victim being her brother Darren, a cycle courier. Darren suffered memory loss but now as his memory returns, he recalls that the package he was carrying was stolen and suspects foul play. His client - and lover - Claudia Scott, imported Moroccan furniture and Jack suspects a drug connection but Darren was also the founder of GLS, an anarchist group committed to ridding London of cars. When Darren is murdered the UCOS team have to find out how he funded GLS and who wanted him silenced.