[Warning: This story contains spoilers for Universal and Blumhouse's Happy Death Day.]

There's good news for fans of Happy Death Day.

The horror film described as Groundhog Day-meets-slasher flick came in at No. 1 at the box office over the weekend, and director Christopher Landon already has an idea for a sequel.

First, a quick look back at what happened (turn back now if you haven't seen the film):

After being hunted by a killer and forced to relive the day of her death over and over, college student Tree (Jessica Rothe) learns the truth. Her roommate Lori (Ruby Modine) was the killer all along. Every cycle for the day, she'd been offering Tree a poisoned birthday cupcake and also setting up killer Joseph Toomes (Rob Mello) as a fall guy to be blamed for the murder. Tree finally breaks the cycle by stopping her roommate. But questions still remain, like: If Tree dies some other way in the future, would she also be stuck in a time loop? Is her mother's death somehow responsible for the time loop? Is there anyone else out there who wants her dead?

In a conversation with Heat Vision, Landon tackles some of those questions and more.

Is the time loop curse truly broken? What if Tree dies again? Is that something we could see explored in a sequel?

I'm trying to keep this close to the vest and be secretive. We don't want to jinx it. We're not counting our chickens and we don't want to operate under the assumption that the movie is going well. We never know how things are going to go. I will say that if we are lucky, and people like the movie and we get to do another one, I do have a sequel ready in my head, and it's definitely not what anyone is expecting, but it will make a lot of sense. And it will answer a lot of questions that may pop up in the first movie for people. But that's only if I get to do it. If I don't, I'm probably just taking it to my grave.

How did you figure out who the killer would be?

The original writer, Scott Lobdell, in his draft I was working off of, Lori and Gregory [Tree's professor, played by Charles Aitken] were the killers together. They were a psycho couple murdering Tree together. That ultimately didn’t work for me. I thought Gregory was a great opportunity to be a suspect. To make him a killer, it didn't help me. That was a change I really wanted to make. And I also  — I loved creating this false ending. And in order to do that, in his old draft, it wasn't Tree's birthday. She never got a cupcake. None of that stuff happened. I thought, if Lori is trying to kill her every day in the start, right from the beginning of the movie was unsuccessful, and ultimately it finally works. That was something I played with. Once I had the Lori thing in place, then it was just about going back and creating, in this type of a movie, credible red herrings. It wasn't a difficult task, because Tree was such an unlikeable person at the beginning of the movie, she has all these people that might want to kill her. That was kind of the fun of the movie, too. She's such a shitty person, that there are plenty of suspects out there. It was something I tried to get into at one point. It's in the script, and it's something that we shot but it ultimately felt like it was dragging the scene out, but when she has that scene with Carter [Israel Broussard] in the cafeteria where he's making the list of suspects, and she's going on and on about all the people that she's pissed off and he's writing them all down, and then he kind of looks at her and he's like, "Your such a terrible person." She finally stops for a moment and realizes, "Oh, my God, I've wronged so many people."

How did your Groundhog Day reference come about?

This is a happy accident. I had written a Groundhog Day reference earlier in the movie in the cafeteria scene, and I had to make some changes to the movie, so that scene we ended up reshooting it. I got rid of it, because I realized it would work so much better at the end of the movie, after we've been through the experience and the whole journey, and if you look at Carter's bedroom, the room, there's a bunch of my favorite movies growing up. There is a They Live poster and a Back to the Future poster, and a Mystery Science Theater poster. This dude knows Groundhog Day. He may be young, but he knows that movie. In reality, most kids their age don't. Tree would never know Groundhog Day. That was part of the fun for me. Playing on these two different types of people who have so much chemistry and work so well together. The most important thing was I wanted I pay respects to Groundhog Day. None of this would be happening without it. It's the granddaddy of all of these movies.

As a man, how did you go about making a mostly female-centered movie?  

I wanted this character to really be an empowered character. I didn't want her to be a damsel in distress. I like that she is so proactive. She has to solve her own murder. She has to be accountable for her actions. She gets to go after her killer, all of those things I thought were really important. One of my movies of all time is Aliens, and Ripley [Sigourney Weaver] is another one of those characters that is so badass and so strong. Strong but so human and vulnerable. I wanted Tree to be all of those things as well. I feel very connected to my female characters — I don't know if that's partly because I'm a gay man.  

What is your favorite scene in the film?

I'm a bit of a sap at heart, and I make scary movies, but I really have this kind of thing. I really do like the scene when she finally meets her dad. It's kind of the culmination of so many things in the movie. Beyond her fighting back and taking her power back, I think she truly becomes a new person when she finally sits down with him and says, "I miss Mom, and I'm sorry that I treated you so badly." It's such a powerful moment for me, because I think it's so hard for people to say I'm sorry. It takes a really strong person to do that.