Guest Stars Barry Sloane as DS Jim Dawson Mark Ivanir as Alexander Goldfarb Daniel Ryan as DAC Peter Clarke Temirlan Blaev as Young Anatoly Litvinenko Kayla Meikle as DC Deborah Maxwell Kirsten Foster as Jenny Hyatt Richard Pepper as DCI Duncan Ball Sam Troughton as DI Brian Tarpey Estella Daniels as Dr Onome George Marcus Onilude as Aidan Maggie Evans as Professor Pat Troop Sarah Naudi as Dr Justine Adams Rad Kaim as Andrey Lugovoy Ian Conningham as Dr Nick Gent Aleksandar Mikic as Dmitry Kovtun Dan Skinner as James Cairns Edward Baker-Duly as Martin Svennson Antonio Magro as Mario Scaramella Kareem Alexander as Michael Simon Paisley Day as Sir John Scarlett