:Episode 4 - Breakout:

Three armed Chechens break into a pharmaceutical plant which carries out tests for Foot and Mouth. Holding a professor at gunpoint, they obtain a phial from a laboratory. A biochemist is shot, but not before she manages to sound the alarm and seal the unit. The thieves are trapped inside, along with three hostages.

Red Troop is summoned and Henno is instantly suspicious - why call the SAS to a break-in at a low security organisation? Smith of MI5 admits some anthrax spores have been released, and imposes a news blackout.

Box 500 hacks into the CCTV cameras and Red Troop see what they are up against. A woman lies still in a pool of blood and one of the Chechens is dead, covered in grotesque blisters. Smith is forced to admit the company has been working on a vaccine for a potent anthrax mutation developed by the Russians and spliced with the flu virus. If the mix is released, thousands of people could die.

Gang leader Ruslan calls for a female doctor to treat Sergei, a Chechen employed by the lab, and Caroline volunteers. Henno follows her intending to use Caroline as a decoy to get the flask, but he is spotted and forced to go inside the building unarmed.

As Dempsey and Dotsy try to work out what went wrong, there is a violent movement on the monitors and terrorist Moussa shoots Henno. His right arm is shattered and he slumps to the ground. Something has to be done fast. Can the team storm the building without being seen, or is blowing up the building to kill the bug - and everyone near it - the only option?