He's writing a new novel. He's been on the wagon for weeks.
5 seconds sound clip from the The Big Knife (1955) movie soundboard.
You can hear this line at 00:15:12 in the Blu-ray version of the movie.
Quote context
[...]
- Are you renewing with Hoff or not?
- Where does Hank get the nerve to propose to you?
- Forget about Hank. He's leaving for New York in two weeks.
- He's writing a new novel. He's been on the wagon for weeks.
- Oh, that again! I never expected to see the day when a firm deal would give you chills and fever!
- I'm as human as the next one.
[...]