The spy drama continues this week when British security is compromised, resulting in a fatal American drone attack on a US army camp. Consequently the head of the CIA travels to England to set things straight at The Grid.

Relations between MI5 and the CIA are fraught at best, but in order to avoid any further secrutiy breaches, Harry has no choice but to agree that Section D and the rest of MI5 use the USA’s security system, Cybershell.

Meanwhile, Lucas is tasked with protecting Daniella Ortiz, an ex-hacker who has turned White House cryptographer. She has the codes to start Cybershell and Lucas must ensure her safety en-route to London.

Back on The Grid, Tariq discovers that their computer systems have been breached by suspected Russian and Chinese hackers who can see and hear their every move. However, once the hackers find out that Tariq and the rest of Section D are aware they have been bugged, they put The Grid’s computer systems on lockdown.

If Cybershell’s codes are successfully delivered Russia and China will have unlimited access to both the UK and the USA’s entire catalogue of intelligence, the consequences of which neither Harry nor the Head of CIA want to even contemplate.

Elsewhere, Lucas is forced to make a tough decision after encountering problems on his journey. Has his personal life finally caught up with him and the secret he is so desperate to hide taken priority over his work at MI5?

Series nine of Spooks continues on Monday nights at 9pm on BBC1.