A routine MI-5 training exercise to handle external calamities turns sinister when the team finds out that the threat is real and that a deadly biochemical weapon may have wiped out the government and most of south London. Amid the chaos, the team has to cope with the situation in the midst of a near total communications blackout. Written by
Did You Know?
When Tom is crossing the bridge near the beginning of the episode he is walking from south to north, but he leaves the bridge onto the south bank. See more
If you don't come to Egypt with me, I break this window.