Tank begins on the banks of the River Dee in the beautiful Roman built city of Chester. An end of term university party is being held on a cruise boat, but the boat is the target of a huge terrorist attack, resulting in the death of hundreds of students. The attacks are laid firmly at the door of Islamic extremists however all is not what it seems. The attack was planned to cover the kidnapping of a Saudi Princess, in an attempt to force up the price of crude oil. Tank and the Terrorist Task Force are called in to lead the investigation. During the plot they stumble over the suspected whereabouts of their Nemesis 'Yasser Ahmed', and their two worlds collide with devastating results.