People often never ask me "What film would be a good starting point if I wanted to learn about film noir?", but if they did ask me one of the films at the top of my list would be T-MEN. A lot of noirs have all kinds of crazy twists and double-crosses and triple-crosses and it's sometime hard to follow, but T-MEN is very straightforward and enjoyable, not to mention the amazing cinematography by John (RAW DEAL, THE BIG COMBO) Alton who had one of the best quotes ever by a cinematographer: "It's not what you light - it's what you don't light."
Anyway, the story is told in a semi-documentary style complete with a narrator. There's a counterfeiting gang run out of Los Angeles that the Treasury Department has been after for awhile, but the only lead they have is there's a connection with another gang in Detroit, so they send two T-men undercover to infiltrate the gang and see what they can find out. That's all you really need to know. I've seen the film a number of times and still I get really into the story, especially the first half where they are working their way into the gang's confidence.
The direction by Anthony Mann is great as is the acting by everybody involved. The main T-man is played by Dennis O'Keefe who's definitely not a household name, but I've always found his career to be fascinating. As far as I can tell there's never been a book written about him, but I've noticed him quite playing a bit parts in various movies, so I found out who he was, looked him up and he's (according to IMDb) been in over 253 movies and TV shows!!! Usually just as a bit part or an extra but still he's been in a ton of films including DUCK SOUP, I AM A FUGITIVE FROM A CHAIN GANG, SCARFACE, LIBELED LADY and even his own TV show that only last 18 episodes! Anyway I just thought that was interesting, because nowadays only the biggest of movie nerds would even know who he was.
Back to T-MEN, one of my favorite scenes has this one guy talking shit right before they kill him, they shoot him and as he's falling down he gasps, full of venom, "You...sucker!" What a badass! LOL. Great movie and worthy of earning a spot in your movie collection.
Another plus for T-MEN is Jack Overman actually gets some respectable screen time. Good for him!