- Captain Warner: You're a bad security risk, Houghton!
- Henry Houghton: Okay, sir, that's it. That's it.
- Captain Warner: I'll have to make a report to the Admiralty about you. Maybe as a civil servant, they can't fire you. But I don't see how they can possibly give you a job with any responsibility again.
- [smash cut to]
- Christina: [Reading a letter from Houghton] Christina Darling - You will be surprised to learn that I have been posted to Portland, the most secret Admiralty base in the country.
- Cmdr. Winters: You can't get in there without a special pass. The whole underwater defence system of Britain's tied up in these few buildings. So you can understand them being a bit particular about it.
- Henry Houghton: I'm gonna miss you. 'Ere. I've got a present for you. Picked it up on D-Day. There you are. Go on - get 'em off.
- [Melodramatic final narration]
- Narrator: But there are still more in our midst. Looking and acting like ordinary citizens. Who knows? There may be a spy, willing or unwilling, in this very theatre, perhaps in the very row where you are sitting. Another link in the same unending chain. As one cell is closed, another opens. And so the dark business of espionage goes on and on.