Sandra Bullock and Melissa McCarthy star in 'The Heat'

A by-the-book Federal agent. A take-no-prisoners Boston detective. Forced to work together to bust a drug ring. It’s the tried and true buddy-cop formula from movies like Lethal Weapon, 48 HRS., and The Other Guys, but director Paul Feig is hoping to prove once again that the ladies can do anything as well as the guys can. In 2011, Feig helped a party of Bridesmaids led by Kristen Wiig and Melissa McCarthy crash the box office to the tune of $169 million, trashing the notion that you need a Y-chromosome to score R-rated hilarity. In The Heat, out in April, Feig and McCarthy are raising the stakes even higher, recruiting Sandra Bullock to bust some crooks in an R-rated action-comedy.

In the new trailer, posted on Apple’s website, McCarthy and Bullock’s characters get off on the wrong foot, but pity the perp who crosses them — especially if he weighs more than they can lift. Feig tells EW about reuniting with McCarthy, what ’80s buddy-cop movie was The Heat‘s real inspiration, and how the movie will showcase another side to America’s Sweetheart Sandra Bullock.

ENTERTAINMENT WEEKLY: Nice trailer. Now which one was Cagney and which was Lacey?

PAUL FEIG: Exactly. It’s a whole new twist, my friend. No, I’m really proud of it because the irony is doing a green-band trailer is kinda hard. We’re definitely a good R-rated movie. But the first trailer definitely gives you a feel for these characters and the chemistry between them. These two actresses are just so funny together. Now they’re like best friends in real life, so the chemistry just comes through.

I assume you and Melissa hit it off during Bridesmaids since you’ve re-teamed again so quickly.

She was off doing Identity Theft [with Jason Bateman] down in Atlanta and I was sad that I wasn’t going to be able to do a film with her this summer, and then this just popped up. As I was reading the script, I was like Oh my God, this is just a home run for Melissa. She read it and just fell in love with it, too. We did one little workshop reading down in Atlanta when she was shooting and Sandra came down for that. They just immediately were funny together. I’m so happy she did this one because she’s playing such a strong, confident, cool character and that’s when I think she’s so funny, when she’s this uncompromising person.

Without knowing them, I still feel like I can say that both actresses share a lot of personal qualities with their characters. Does that seem fair?

I’d say there are traces of absolute truth in that statement. That’s my favorite way to do comedy: you cast really funny, great people, and then you try to find how to make [the characters] close to who they are, or find elements of their personality. It just makes it so much more real. You just buy what they’re doing. Sandra’s character is named Sarah Ashburn, and Sandra has very Ashburn-ian qualities. She’s very by-the-book, and she has a very distinct way she likes to do things, and she’s a very together kind of person. And Melissa is just this force of nature who doesn’t hold back. So you understand how reading the script for the first time, I was like, Wow, this is just tailor-made for the girls.

The trailer gives us some clues, but what else can you tell us about their characters and the plot.

Ashburn’s been in the FBI for a long time. She’s a great agent but she’s slightly over-confident, a little intolerant of anybody who isn’t at her level, so she showboats a little bit. She gets sent to Boston to help crack this case about this drug lord that nobody can figure out. And she has to work with Melissa’s character because Melissa’s a street cop who knows the neighborhood and has a brother who’s been kind of involved in the world of this guy they’re trying to find. But she’s used to doing everything by herself. She’s a one-woman police force, so she doesn’t like having to help people. They band together, but it takes a long time for them to bond. Sandra’s character is very psychological, she’s really about how to psychologically get inside people’s heads without force and befriending them. Definitely good cop. And Melissa is just pure force. Forcing people to do what she wants them to do. So the fun starts there.

Did you set out to reference any favorite movies, whether it be Boston movies, or cop movies, or female-starring movies?

Yes and no. To me, the inspiration for this — tonally and everything else — was 48 HRS. We have this amazing writer Katie Dippold, who comes from Parks and Rec, and our goal was not to make this at all a quote-unquote ladies movie or a chick flick. Katie was inspired by one movie; I think the one with Billy Crystal and Gregory Hines…

Running Scared.

She’s like, there’s this montage where the two of them are riding on mo-peds and they have all these hot girls behind them. She’s like, “Why can’t women have that?” We’re not making them talk like guys, but at the same time, they aren’t running around afraid to shoot a gun. It’s not about romance or anything. I wanted it to be kind of groundbreaking in that way because I feel like so much stuff for women always has to have, “Okay, we have to have some nod to the ladies.” Nah, nobody is desperately trying to find a boyfriend, or is upset about this or that. It’s cool to play two women characters who are just great at what they do; them being women doesn’t effect anything really other than that these are two funny women. They’re just doing their jobs and trying to work together.

Sandra has done just about everything during her career: action, comedies, dramas, romances. What do you think audiences will be most surprised by her performance in this?

Comedy is ever-changing and this brings Sandra to this latest phase of comedy which is just — you know, it’s R-rated and she really gets to have fun with that. So I think people will be surprised at some of the stuff she gets to say and do in the movie.

Hollywood can sometimes feel like the world of “No” for a filmmaker, but I’m guessing after the success of Bridesmaids, that word went on vacation. Have you gotten used to hearing “Yes?”

No, because the minute you get comfortable with it, you begin to make mistakes. That’s where a lot of people I’ve seen go off the rails, because then you’re kind of unchecked. You have to say “No” to yourself more than anybody else does. It was a long road for me to figure out what I wanted to do after Bridesmaids. I developed a lot of stuff; I was attached in and out to various things, but nothing felt like that home run. You know, you’ve got to be very hard on yourself. I could have easily jumped into a bunch of different movies that may or may not have been satisfying to the people who liked Bridesmaids. I take that very seriously. Some filmmakers are like, “You don’t want to be beholden to the audience,” but I’d rather be a little beholden to the audience because they’re the ones that put us where we were with the first one. What I want to do is take the cachet and the goodwill that we got from Bridesmaids and take it into a different movie. You don’t want to make the same movie again, but at the same time I love making movies with women and strong women characters. So I just kept looking for that thing, and when this came across my desk, it felt like the perfect followup. It just felt like the right move.