The Virus, Part 1

S6 E1: The team is sent undercover in Iran when they receive intelligence that suspected terrorist Mehan Asnik is plotting a bomb attack on London. Their aim is to blow up Asnik in Tehran, making it look like a terrorist attack, but just as the team are about to detonate the charge, a train packed with civilians pulls up yards from the target. With the operation at a critical stage, the team must make a split-second decision that could cost many innocent lives.