 Meanwhile , Malcolm Wynn @-@ Jones ( Hugh Simon ) discovers a communication burst coming from the North Sea , believing a Russian submarine is entering British waters unannounced to carry out a mission . After learning that Alexander <unk> ( Georg <unk> ) , a man with connections to Kachimov , is going to shut down his company 's servers , Malcolm confirms his suspicions ; the Russians are planning a cyber attack against Britain by breaking into a submarine communications cable and shutting down every computer system in the country . Harry urges Dolby to temporarily shut down the Internet , but is once again denied . Later , Ros breaks into Lucas ' flat while he is away , and discovers Lucas is a double agent , feeding the Russians news that MI5 know about their planned attack . Ros tasers Lucas and brings him back to Thames House . Lucas admits he is spying for the Russians because Kachimov promised he would be released from prison sooner if he would , but also reveals he intends to bring Kachimov down by making him trust Lucas . 
