Mark Halliday [to Margot]
Darling, I understand now, but that doesn't stop me from loving you.
Played by Robert Cummings 
Dial M for Murder (1954) · 18 quotes
Dial M for Murder (1954) · 18 quotes
Tied for 3rd most-quoted character in Dial M for Murder (1954): in 5 of its 18 quotes
Most scenes with: Tony Wendice (2), Chief Insp. Hubbard (2)
Scenes with Mark Halliday
5 scenes Mark Halliday 
How do you go about writing a detective story?
Mark Halliday Well, you forget detection and concentrate on crime. Crime's the thing. And then you imagine you're going to steal something or murder somebody.
Oh, is that how you do it? It's interesting.
Mark Halliday Yes, I usually put myself in the criminal's shoes and then I keep asking myself, uh, what do I do next?
Margot Mary Wendice
Do you really believe in the perfect murder?
Mark Halliday Mmm, yes, absolutely. On paper, that is. And I think I could, uh, plan one better than most people; but I doubt if I could carry it out.
Oh? Why not?
Mark Halliday Well, because in stories things usually turn out the way the author wants them to; and in real life they don't... always.
Hmm.
No, I'm afraid my murders would be something like my bridge: I'd make some stupid mistake and never realize it until I found everybody was looking at me.
Sooner or later, he'll come back here. As I've pinched his latch key, he'll try the one in the handbag. When that doesn't fit, he'll realize his mistake, put two and two together, and look under the stair carpet.
Mark Halliday If he doesn't do that, all of this is pure guess work. We can't prove a thing.
That's perfectly true. But once he opens that door, we shall know everything.
Mark Halliday When did you find out, sir?
Well, the first clue came quite by accident. [to Margot] We discovered that your husband had been spending a large number of pound notes all over the place - it ran into over three hundred pounds - and it appeared to have started at about the time you were arrested. Now, I had to find out where he got that money, and how. Then I remembered that after you were arrested we searched this flat, and I saw a copy of his bank statement in that desk. So yesterday afternoon, I went to the prison and asked to see your handbag. While I was doing this, I managed to lift your latchkey. Highly irregular, of course, but my blood was up. And then this morning when your husband was out, I came back here to look at his statement. I never saw it... because I never got through that door. You see, the key that I'd taken from your handbag didn't fit the lock!
[Tony has just been caught]
As you said Mark, it might work out on paper, but... Congratulations, Inspector. Oh, by the way... [makes himself a drink] How about you, Margot?
Margot Mary Wendice
Yes, I could do with something.
Mark?
Mark Halliday So could I.
I suppose you're still on duty, Inspector.
