- Inspector Regan: Kelly, you stay here. It might do you a little good to meet a real detective.
- [after a pause]
- Inspector Regan: Ask Mr. Chan to come in.
- Sergeant Kelly: Wait a minute! You haven't called Chop Suey in on the case? Have you, Chief?
- Inspector Regan: No, but it's not a bad idea, and take your hat off! You could learn a little politeness from the Chinese too!
- Sanatarium Guard: Say, I worked around sanitariums before. It's not so bad. I like the cuckoos myself. They're the same as anybody else, only they're smart enough to admit they're nuts.
- Sergeant Kelly: [looking at a note written in Chinese] What's that? A laundry list?
- Charlie Chan: Much laundry, but all dirty.
- Mr. Arnold: My name's Arnold. I'm stage manager here, and this opera is going on tonight even if Frankenstein walks in.
- Charlie Chan: Very old Chinese wise man once say, "Madness twin bvrother of genius because each live in world created by own ego. One sometimes mistaken for the other."
- Charlie Chan: Case still wide open like swinging gate.
- Sergeant Kelly: Watta yuh mean?
- Charlie Chan: Gravelle not murderer.
- Inspector Regan: Not Gravelle?
- Charlie Chan: Excuse please, will demonstrate hypothesis.
- Sergeant Kelly: What?
- Charlie Chan: Word of Greek origin, hypo meaning...
- Sergeant Kelly: [interrupting] Hypo! I get it! He's hittin' the pipe again!
- Mme. Lucretia Borelli: Is this some ridiculous attempt at saving your face, Mr. Chan?
- Charlie Chan: Humble countenance merely facing facts.
- [last lines]
- Lee Chan: I knew we were on the right track Pop! The first time I saw Madam Borelli, I was sure she was guilty, because...
- [the visor on his helmet slams shut, cutting him off]
- Charlie Chan: Case now closed.
- Inspector Regan: [after examining the card that Mme. Rochelle said she received attached to the basket of flowers, and which reads "You Will Die Tonight"] Perhaps you are right, Charlie: our madman does know Mme. Rochelle!
- Mme. Lilli Rochelle: I told this officer that I do not know your escaped maniac!
- Enrico Barelli: Madame meets many people but she usually avoids the mad ones.
- [first lines]
- Sanitarium Guard 1: What's the mater Joe? Nervous?
- Sanitarium Guard 2: Aw this job gives me gooseflesh. You're new here, but in a couple of months you'll get as jumpy as me.
- Sanitarium Guard 1: Hey I've worked around sanitariums before, it's not so bad. I like the cuckoos myself. They're the same as anyone else only they're smart enough to admit they're nuts.
- Sergeant Kelly: [to Mr. Chan, after the case has been solved by Chan] You're all right. Just like Chop suey. A mystery - but a swell dish.