->''An old flame returns.''

''Hello Mary Lou: Prom Night II'' is a 1987 sequel to ''Film/PromNight1980''.

The film centers around the ghost of one Mary Lou Maloney, a girl who was accidentally killed during her prom queen crowning in the 50s. Her spirit is accidentally released by a girl named Vicki when she finds her supposed prom queen regalia in the school's prop room. Mary Lou possesses her, and sets out to get revenge on those responsible for her death and become the prom queen once more.

The movie actually has nothing to do with the original ''[[Film/PromNight1980 Prom Night]]'', [[InNameOnly other than the title]], and the film's school having the same name (this is a coincidence). It was filmed as its own independent movie as "The Haunting of Hamiltom High", but the studio purposed it as a sequel to ''[[Film/PromNight1980 Prom Night]]'' in an attempt to make more money. The producer, Peter Simpson, blames this for the film's box office failure, and insists that it should be watched as its own movie, not a sequel.

The film has developed a small cult following following its release on home video, and got a direct-to-video sequel of its own: ''Film/PromNightIIITheLastKiss''.

!!This film has the examples of:

* {{Adorkable}}: Josh, genial supplier of (often lewd) quips and inventor of the (ineffective) potato-powered radio.
* AccidentalMurder: Mary Lou's death is caused by Billy dropping a stink bomb on her as she is crowned, which ignites her dress, turning her into a [[ManOnFire Woman on Fire]].
* AlphaBitch: Mary Lou when she was alive, and Kelly in the present, though Kelly is more of a [[DeconstructedTrope deconstructed]] type; venomous to her rivals but nice to everyone else, with [[SourOutsideSadInside hints of insecurity.]]
* AmbiguouslyBi: Mary Lou, as suggested during the scene of her in Vicki's body walking into the girl's shower room completely naked to kiss Monica on the forehead. Monica might count as well, as she is shown enjoying the kissing at first.
* BewareTheNiceOnes: Vicki loudly calls Kelly a bitch for mocking Jess after her death, and also proceeds to slap her.
* CreatorCameo: Just before the climax, writer Ron Oliver plays a prom attender who makes an unwitting DoubleEntendre.
* DeadlyPrank: Billy simply tried to embarrass Mary Lou as a revenge for cheating on him and rubbing it in his face, but instead caused her death.
* DemonicPossession: Once Mary Lou's spirit is freed, she starts harassing Vicki until she manages to take over her body.
* DepravedBisexual: Mary Lou swings both ways, as evident on her attempt to seduce Monica.
* DisproportionateRetribution: Jess chips off one of the rhinestones on the prom queen tiara, which causes Mary Lou's spirit to violently toy with her by dragging her around the art room by the cape from the trunk, making it look like that she is going to chop he head off with a paper trimmer before [[KillerOutfit hanging her by the cape]] and then [[DestinationDefenestration throwing her body out the window]].
* DownerEnding: [[spoiler:Mary Lou is subdued by now older Billy by putting her prom crown on her head, which presumably satisfies the conditions of her revenge. He also decides to steal a kiss from her as a form of trying to make right what happened 30 years ago. Cue romantic flash back to the original prom. What is actually happening is that the prom queen is using the opportunity to BodySurf into the guy, who then goes on to (presumably) kill his children off-camera. So, essentially, TheBadGuyWins.]]
* EstablishingCharacterMoment: Mary Lou's first scene has her going to a {{Confessional}} and listing various adulterous behaviour to the priest. But instead of asking for forgiveness, she instead tells him that she loved every minute of it and scribbles "For a good time call Mary Lou" on the confessional booth's wall with her lipstick.
%%* EvilIsPetty: Is. It. ''Ever''.
* HighVoltageDeath: Mary Lou electrocutes Josh as he tries to rig the prom queen vote tally for Kelly's favour with his computer.
* LaserGuidedKarma: Smug Kelly ends up having to give [[SexForServices a blow job to win the title of the prom queen]], doesn't get it, and [[spoiler:is killed completely by accident when she gets stabbed in the chest when one of the neon lights in the auditorium comes loose during Mary Lou's rampage.]]
* MadeOfPlasticine: That neon light doesn't really look like its hitting [[spoiler:Kelly]] that hard. It just kinda... falls against her. It seems like impalement would take more force.
* MindOverMatter: Mary Lou kills [[spoiler:Monica]] by crushing her inside the locker that she's using to hide from her.
* MyBelovedSmother: Vicki's mom comes across as a ''really'' watered down version of Margaret White, though thankfully her dad is still around and he is much more understanding.
* NotMyDriver: [[spoiler:The film ends with our protagonists getting in a car that's being driven by Mary Lou. It is likely that they were killed by her]].
* ParentalIncest: Late in the movie, Mary Lou (while controlling Vicki's body) seduces Vicki's father and later tries to seduce her mother when she walks in on them, before ultimately killing them both.
* PercussivePrevention: In order to protect him, Principal Cooper knocks out his son Craig when he tries to go look for Vicki.
* ReallyGetsAround: Mary Lou when she was still alive, which ultimately led to her [[{{Cuckold}} cuckolded]] boyfriend Billy accidentally killing her.
* SequelTheOriginalTitle: Done by combining TitledAfterTheSong ("Hello Mary Lou" is a pop song from the sixties) and NumberedSequels.
* ShoutOutThemeNaming: Plenty of characters share surnames with famous horror creators: [[Creator/WesCraven Craven]], [[Creator/StephenKing King]], Romero, Browning, [[Creator/JoeDante Dante]], [[Creator/JohnCarpenter Carpenter]], [[Creator/JohnWaters Waters]], Henenlotter....
* ShowerScene: Gratuitous nudity is provided when Mary Lou, in the guise as Vicki, tries to seduce Monica while she is taking a shower.
* SlidingScaleOfComedyAndHorror: This film has a much lighter tone than the previous ''Prom Night'', and could be considered a black comedy, but still has enough genuine terror to split it about half/half.
* SpeakIllOfTheDead: Kelly, being the AlphaBitch that she is, does this after Jess' death, (specifically the ''day after her funeral'') straight to the faces of the latter's best friends, Vicki and Monica, no less! Vicki understandably doesn't take it well.
-->'''Kelly:''' The competition seems to be dwindling. You two should take the hint from Jess.
-->'''Vicki:''' You shut your ''[[PrecisionFStrike fucking]]'' mouth, ''[[ThisIsForEmphasisBitch BITCH]]!''
* SourOutsideSadInside: Kelly's attempt to bribe Josh to rig the voting tally, and her sad, defeated reaction to his [[SexForServices price of fellatio]], hint at insecurity.
* TheVamp: Mary Lou was an evil bitch even before she died; killing her just gave her a power boost.