Guest Stars Barry Sloane as DS Jim Dawson Mark Ivanir as Alexander Goldfarb Daniel Ryan as DAC Peter Clarke Kirsten Foster as Jenny Hyatt Richard Pepper as DCI Duncan Ball Kayla Meikle as DC Deborah Maxwell Temirlan Blaev as Young Anatoly Litvinenko Sam Troughton as DI Brian Tarpey Marcus Onilude as Aidan Nikolai Tsankov as Boris Berezovsky Stephen Campbell Moore as Ben Emmerson QC Selina Cadell as Louise Christian Brian Protheroe as Sir Robert Owen Greg Kolpakchi as Oscar Enrique Kevin Shen as Robin Tam QC James Esler as Older Anatoly Litvinenko