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