Well, it's a prison movie. With two about-to-be big stars, Burt Lancaster and Hume Cronyn. And a bunch of supporting actors who would go on to be on Star Trek one day: Whit Bissell, Jeff Corey, John Hoyt, John Harmon, and Tom Steele!
OK, I had to have IMDB help for those last two.
But there's also Mrs. Munster, Yvonne De Carlo. And the bad sister from Mildred Pierce, Ann Blyth. And… well, you can read IMDB as well as I can.
There's also a lot of pretentious dialog, and—I think—ham-handed symbolism, but I tend to ignore that. (The director was ex-Commie Jules Dassin.)
Set in a brutal prison. With a brutal Hume Cronyn running the show, easily bypassing the effete warden. He gets his kicks from inflicting pain (mental and physical) upon the cons he dislikes. Which includes Burt Lancaster, the noble victim who decides to hatch an audacious escape plot while in solitary confinement.
The convicts are a decent lot in comparison. Oh, sure: sometimes they need to inflict their own brand of rough justice on stoolies. Fortunately, they work in a shop where there's a massive piece of machinery that's ideal: I'm pretty sure it's called the Stoolie Masher.
Everyone seems to be in the joint because of some dame, though.
Anyway, the escape attempt, when it finally happens, is pretty spectacular and violent for 1947.