The Special (Part 1) is the first episode of spook's fourth series which aired for the first time on 12 September 2005.
Summary
A bomb detonates nearby Danny's funeral. Section D investigate and learn that an American-based terrorist group, "Shining Dawn", who believe the human race ought to be culled, are responsible; they demand the release of their leader from British custody, or they detonate a bomb in public places every 10 hours.
Ruth visits a sympathiser, Curtis, who is targeted, while Adam and Zaf follow leads, and discover there is a mole in MI5, as both suspects end up dead. They do eventually find the next bomb in Marylebone Station and defuse it. Adam also tracks down a witness, Natasha Scott (guest star Martine McCutcheon). Zaf is captured by Shining Dawn members.