I Spy Apocalypse

S2 E5: The team is busy at work when an alarm goes off. Everyone groans - it's an EERIE (Extreme Emergency Response Initiative Exercise). They must act exactly as if there's a national emergency - in this case, germ warfare in Central London. As the exercise goes ahead, information dries up, power and phone lines go down, victims try to break into Thames House - and suddenly Harry gets sick. The team tries to stay calm, but doubts start to set in, is this actually for real?