The Japanese changed the J-N25 code, that's the one that's been giving us Yamamoto's plans.

5 seconds sound clip from the Midway (1976) movie soundboard.

You can hear this line at 00:29:11.634 in the Blu-ray version of the movie.

Quote context

[...]

- No, sir. My orders were simply to consult. No, sir, I have no such orders for you.

- Commander Blake, declare a state of fleet-opposed invasion. Target: Midway Island. Issue the order immediately.

- Aye-aye, sir.

- Admiral, may I see you alone a moment, sir? Excuse me, Captain.

- Damn. You know how much Bill Halsey hates hospitals.

- Well, maybe it's not that serious, sir.

- If he scheduled himself to go anywhere near one, I'm sure it's not only damn serious, it's probably critical.

- Admiral, I got some really bad news.

- Today is the day for it.

- The Japanese changed the J-N25 code, that's the one that's been giving us Yamamoto's plans.

- How long will it take you to unravel their new system?

- A month, maybe two.

- Sir, do you still want that fleet order issued?

- Yes. Target: Midway.

(Japanese navy men playing bugles)

- Welcome aboard your flagship, Admiral.

- Thank you, Captain.

[...]