When the High Court finds the warrants were unlawful, the police investigation comes to an end. But Barry is concerned that he may have been placed under surveillance and he approaches the only court in the UK which can tell him if that’s true.

The Investigatory Powers Tribunal has the power to find out if he was spied on unlawfully, but rarely find in favour of claimants. Years pass with no response – then, an unexpected revelation. One that will have far-reaching consequences for journalists and multiple police forces.