Every mystery must come to a satisfying conclusion (well, okay, at least a conclusion) and in the case of I Know What You Did Last Summer, that means we need to finally unmask the killer who has been stalking the teens involved in the coverup of Lennon Grant's death. With the dead bodies piling up, our suspect list keeps getting shorter, and shorter — and thus far, there's no one obvious suspect to point to.

However, while motives are blurry at the moment, they are bound to become crystal clear once the show finally reveals who is behind all the bloodshed. The only thing we can do right now is theorize with all the clues that the show has given us thus far — even if they are slim pickings.

Here are our list of suspects who totally know what happened last summer...and want revenge, one way or another.

Allison & Lennon's Mom

I was pretty convinced that Allison and Lennon's mom was the murderer for a while, especially considering how much emphasis they put on the mother favoriting Allison (the allegedly dead twin) over Lennon. However, in episode 7, it's revealed that the mom had a new family and little interest in parenting her teenage twins. More significantly, it seemed she didn't even know about Allison's death, which would have been a key motivator. She returns in the final moments of episode 7 to confront her ex-husband Bruce, so it's possible she's just pretending to be cold and aloof in order to throw suspicion off of her as she gets revenge on those who wronged "Allison."