The killer in the Amazon Prime Video reboot of I Know What You Did Last Summer is revealed to be Margot. Despite initial suspicion falling on Dylan, who was acting suspiciously and involved with a cult, it is Margot who is the real murderer. The revelation occurs when Dylan and Allison discover Margot's mother's body at the cult compound. Margot then attacks Dylan and Allison, confirming her as the killer
. This differs from the original 1997 film, where the killer was Ben Willis, the man who was hit by the car and left for dead. The Amazon reboot introduces new characters and a new killer, keeping viewers guessing throughout the season
. The cast of the reboot did not know the killer's identity during filming and even placed bets on who it might be, highlighting the show's use of misdirection
