It's both Friday the 13th and October 31st -- the worst bad-luck day ever! The ghouls are freaking out. Will Ghoulia's killer plan create more chaos or save the day?
Frankie is shocked to find the school overrun by misfortune, such as ghosts chasing some of her fellow students. One swoops by Deuce Gorgon, whose path is crossed by a black cat. He stumbles backwards into a locker, causing his sunglasses to fall off, and he spots himself in a mirror, turning himself into stone. Mr. Hackington steps on a crack in the floor, causing his mother's back to make a cracking sound.
Looking for answers as to what is going on, Frankie turns to her friends. Draculaura tells her it is "a confluence that happens every thousand years" — it is both Friday the 13th, and also the 31st of October, the worst bad luck day possible. Lagoona adds that the bad luck ends when the bell rings at three o'clock, but that won't be until six more hours. Cleo tells the ghouls not to worry, as she has the amulet of Knuck'n'nothin', which protects the wearer and anyone nearby from misfortune. On Frankie's inquiry where the amulet is, Cleo replies that since it doesn't go with her outfit, Ghoulia is carrying it for her. Looking aside of her though, she realizes her friend is nowhere around. Before anyone can freak out, Lagoona spots Ghoulia as she's shuffling away, the misfortune around indeed not ever affecting her.
The girls run after her, witnessing other people's misfortune and suffering much themselves too. They nearly get the next floor on their heads, then nearly some lockers, then they get electrified by a local storm (which Frankie only finds refreshing), and Clawdeen nearly run over by a giant disc. When they finally catch up with Ghoulia, they find her on a ladder climbing to the top of the giant clock in the school's main hallway. Ghoulia moves the clock's hands to three o'clock, ending the day's bad luck spell. The girls congratulate her for her cunning, while Ghoulia points out the amulet does go with Cleo's outfit.
- Frankie herself points out that it is impossible for Halloween to be on the same day as Friday the 13th.
- Hackington's action of stepping on a crack and the woman complaining about her back is a reference to the children's rhyme "Step on a crack, break your mother's back".
- A jinx is a curse of bad luck. One myth of bringing it into existence is by two people saying the same thing at the same time. Whoever of the two says "jinx" first after it is spared the curse, while the other has to suffer it for an indeterminate amount of time.
- Cleo calls it the Amulet of Knuck'n'nothin', which is a play on the name of the pharaoh Akhenaten. The amulet is in the shape of an ankh, the Ancien Egyptian key of life.
- Although Deuce manages to petrify himself in "Freakout Friday", the myth states that a gorgon's reflection is harmless and cannot turn someone to stone. Deuce will get petrified by his reflection once more in the TV special "Escape From Skull Shores", so a gorgon's reflection is just as harmful as a direct gaze in the Monster High universe.
- This is the first time that Cleo uses an Egyptian artifact to her advantage.
- Frankie will respond again to being hit by lightning with an exclamation of "Refreshing!" in "Screech to the Beach".
- The black cats and giant South American-ish disc return in the Volume 2 Friday the 13th webisode "Frightday the 13th".
- Bloodgood's headless body evidently can't see without the head's eyes, but it supposedly can hear without the head's ears.
- Cleo's art and animation when she gets electrified was also used in the TV special "New Ghoul @ School" when Frankie asks her to sign the petition.
- The model of the Amulet of Knuck'n'nothin' will be reused once for an artifact of a very different nature. In "Queen of the Scammed", Cleo uses it to put her atop the school hierarchy again, though instead it ends up unleashing one of the Ancient Egyptian plagues.