So I Married an Axe Murderer

Rose, Harriet's peculiar sister, is actually Mrs. X. She has been killing Harriet's husbands during their honeymoons because she believes they are usurping her place in her sister's life. Rose brandishes an axe and reveals her identity during Charlie and Harriet's honeymoon, confirming she is the real serial killer, not Harriet.

Meeting Rose earlier in the film serves as a warning about potential dangers in the relationship, foreshadowing her later revelation as the killer.

Charlie became suspicious of Harriet because his mother May told him the chilling legend of Mrs. X, a bride who murders husbands during honeymoons. Additionally, Charlie learned about Harriet's past in Atlantic City, her relationship with a Russian martial arts instructor, and heard her cry out for someone named Ralph in her sleep, fueling his doubts about her true identity.

May's tales of Mrs. X loom over the entire relationship, creating suspicion whenever Harriet exhibits any mysterious behavior.

Harriet's previous husbands did not simply disappear, they were murdered by Rose during their honeymoons. Rose left deceptive letters at the scenes to make it appear as if the husbands had abandoned Harriet. Harriet believed each husband had simply walked out on her, never knowing her sister was the culprit.

The news of the martial arts instructor's murder (Ralph) connects to this revelation, showing a pattern Charlie initially fails to recognize.

Rose killed Harriet's husbands out of twisted jealousy. She believed each husband was stealing her sister away from her, so she eliminated them on their honeymoon nights to keep Harriet to herself. This pathological possessiveness drove her to commit multiple murders while framing the disappearances as abandonments.

Charlie notes Rose as a stark reminder of potential dangers when they first meet, hinting at her dangerous nature.

Tony discovered the truth by sending Harriet's photo to the families of the missing husbands, who identified her as the wife of their dear friend. This led Tony to realize that Harriet was not the killer but rather the target. He then realized the self-declared killer was a master of deception and a red herring.

Tony's detective instincts throughout the film build toward this revelation, particularly his investigation into the supposed confessed killer.

Charlie locked Harriet in the closet because he believed she was Mrs. X and intended to kill him during their honeymoon. Unable to receive Tony's warning due to the power outage and consumed by fear after seeing news reports about the murders, Charlie panicked and restrained Harriet to prevent what he thought was an imminent attack.

The power outage preventing Tony's call builds tension that culminates in Charlie's desperate action.

Ralph was simply a friend to Harriet, not a romantic partner or suspect. Harriet cries out for Ralph in her sleep because he was a significant person in her past, but when she explains this to Charlie, she clarifies that Ralph is merely a friend. The real Ralph was a martial arts instructor who was murdered by Rose, adding to the confusion.

The murder of the martial arts instructor (Ralph) creates a false connection that fuels Charlie's suspicions.

The confessed killer was a red herring. Tony discovers that the self-declared murderer who confessed to the crimes is actually a master of trickery and deception. This false confession was meant to mislead the investigation, and it successfully provided Charlie with a false sense of relief before the true events unfolded.

The news of the confession early in the story creates temporary relief that makes the actual twist more surprising.

The power outage at the hotel prevented Charlie from receiving Tony's urgent warning about Harriet's connection to the murders. Tony had tried to contact Charlie to reveal that Harriet was actually the target, not the killer, but the storm and power failure left Charlie in the dark about the danger approaching from Rose, not Harriet.

The storm interrupting communications builds suspense leading to the climax.

Harriet accepted Charlie's proposal with apprehension because she knew about her sister Rose's pattern of killing husbands. While Harriet believed her previous husbands had simply abandoned her, she may have subconsciously sensed something was wrong. Her hesitation reflects an underlying awareness that her relationships tended to end tragically, even if she didn't understand why.

The earlier mention of Harriet's apprehension during the proposal hints at her unconscious knowledge that something is wrong with her marriages.