False Flag: Part 2 (S04E04)

Boyd is told by an ex-army officer that the security services did not always play fair in Northern Ireland in the 1970s. When he discovers that his car has been bugged, he realises that things haven't changed. The ex-officer promises Boyd new evidence, but is killed in a car bomb before he can deliver it. As the evidence starts pointing back to the assassinated Government minister, the solution appears to be clear. (iTunes)