Their task is to befriend Oliver "Oli" Lakshmi, a troubled youth and potential recruit for CHERUB with a reputation for elaborate but untrue stories who claims to have information on radical Islamic terror groups.

Ryan and James investigate and find that Offshore Marine Exploration is a defunct oil company whose equipment is still used in the Middle East.

The other two engineers have gone missing, and James deduces that they were captured by the Islamic State to maintain a network of IS-controlled oil wells using OME equipment.

He recruits his sister Lauren Adams, his fiance Kerry Chang, and his friends Kyle Blueman and Bruce Norris, along with Israeli intelligence officer Tovah.

In the epilogue, Uncle is sentenced to life in prison for terrorism and money-laundering offenses; Ning retires from CHERUB and begins dating Bruce; Ryan reunites with Natalka and brings her to live with him in the UK while he attends university; Lauren becomes a racecar driver; Kerry becomes a mission controller; James and Kerry marry, and announce that they are expecting their first child.