Mary is a character from the animated series, The Invisible Man. She is Linda's best friend and Monty's girlfriend. In "Halloween Express", she and her friends travel to the Arkham Mansion to spend the Halloween weekend. But they meet a nefarious ghost who is set on putting a spell on them and taking over Magnapolis. Mary and the others have to find a way to get him back to the mansion, and have him ghosted.
About Mary[]
Mary and her friends ride with Todd to the Arkham Mansion where they're to visit for the Halloween weekend. As Todd drives, he asks Mary how she likes the aero car, the Turbo VXL. She says she likes it and says how nice it is of him to take them there. When they arrive, they meet Alan and his monkey sidekick, Photon, before going inside the haunted mansion. As they go farther inside it, Mary comments on how the smell of it reminds her of her grandmother's attic. After Alan finds the switch to turn on the light, Mary and Linda are concerned about there being ghosts around, but Todd says he'll protect them should there be any. After Linda cleans up all the filth with her portable vacuum cleaner, she asks the others if any of them are aware of a factoid about dirt and dust. Mary interrupts her before she continues, insisting they're already aware of the info from an article she wrote about that. Monty begins to tell a ghost story, but Alan leaves the room for a moment, claiming he has to get more firewood for the fireplace. Monty begins to tell the ghost story when he and the others suddenly hear a spooky moan. What enters the room seems to be a ghost and Mary, and most of the others, are scared out of their wits. Linda initially isn't convinced, thinking instead that it's just a prankster wearing a ghost costume. When she removes the sheet, a floating Jack-O'-Lantern is revealed and Linda becomes frightened as well. The prankster is shown to be Alan, who was able to pull the prank off due to his invisibility ability. Mary and the others aren't amused by this, but Alan finds it to be a riot.
Afterwards, Mary asks Todd to tell a story and Monty asks him if he has one having to do with soccer. Todd says he has a story of his own about the two prettiest girls at the university where they all attend, talking about Mary and Linda, both of whom are flattered. Before Todd can keep going with the storytelling, he sees a large shadow on a wall of what seems to be a monster, but it's really just a tiny spider lowering from a ceiling and gets on the palm of Monty's hand. Monty takes delight in poking fun at Todd's fright, tossing the spider onto Todd as he struggles to get it off his chest frantically. Monty has a laugh, but Mary isn't pleased with this, telling Monty how much he can be such a fathead at times. As soon as she says this, Monty suddenly inflates like a balloon and as soon as Monty calls Todd a chicken, that's literally what Todd becomes. Mary and the others are shocked, and have no idea just what's going on exactly. Todd approaches Mary and clucks. She asks him to cluck slowly as she can't quite understand him. Gina theorizes that Monty and Todd became other things when the very thing they became were mentioned, but she doubts that's possible despite seeing it before her very eyes. Mary picks up Todd and holds him while sticking him in her face, asking her what she calls this. As Mary refers to Gina as "Little Miss Encyclopedia", Gina turns into one. Everything is explained once the real ghost, The Sorcerer, appears. He says that the transformations were caused by him. When Photon attempts to attack The Sorcerer, he goes through the specter's transparent body. The Sorcerer presumes Photon is unintelligent. Mary admits he's theirs, but he's not dumb. When Mary and her comrades hear Photon speak, they're surprised. After The Sorcerer exits up the fireplace and chimney, Alan says they've got to put a stop to him. Mary has no idea how, since everything simply goes through him. Gina speculates that The Sorcerer is made of ectoplasmic particles and Linda says he should be easy to capture by using her vacuum should he come back. Alan says that's a great idea and begins to take Linda's vacuum, but she tells him he and everyone else will need his/her own since she has extras. She says she'll bring the others, but Gina thinks it would be much better to stay together so they can work as a team and asks her to stop being so hyperactive. That's the very thing Linda becomes involuntarily. Sarcastically, she thanks Linda for that. As they go through the hallway and upstairs, they then enter the mansion's library. When the Sorcerer reappears, Alan uses his vacuum to suck and trap him in it. But the Sorcerer tricks him to let him out and goes off to downtown Magnapolis to wreak havoc. Everyone is left with having to figure out a way to get him back.
Following a chat Alan and Photon have with each other, Mary and some of the others head to the aero car as they're on their way to downtown. Monty and Todd stay behind at the mansion. As Mary drives, at one point, she points out that there are so many abandoned aero cars on one street, due to being affected by the spell also. Eventually, they see The Sorcerer on a giant screen on a building and he announces that if a spell book he's looking for isn't brought to him within a certain amount of time, he'll seize the area. Mary and the others then head to the Arkham Museum to find a book containing information on how to do away with the Sorcerer. After getting there and entering, they find the book under a display case. Alan reads about how it is done, but before he can complete the whole thing, the book dissolves into dust from being so antiquated. Returning outside, Alan says there must be another way to stop The Sorcerer. Mary doesn't see how as it seems they're stuck in their predicament and time is getting shorter. When she and the others watch The Sorcerer searching through a pile of books for the one he wants outside a public library across a street, Alan comes up with the plan of using Gina as bait to make The Sorcerer think she's the correct piece of literature he seeks. After getting his attention, The Sorcerer goes after Alan, who's now invisible, and Gina, who flee back into the aero car. When Alan says, "Now!", Mary floors it and The Sorcerer follows them all the way back to the mansion. Upon returning there and realizing that he's been tricked, The Sorcerer is in the mansion's library with the visitors again. The plan isn't quite successful as he tells them that now they're prisoners and condemned to the mansion as well. Alan comes up with yet another plan, whispering it in Monty's ear. Monty compliments Mary by saying her beauty reminds him of the sun's rays. Mary is literally beaming as rays of light shine through her body. This causes The Sorcerer to be destroyed once and for all, the spell is broken, and everyone is back to normal. Exiting the mansion once more, Mary tells Monty that his compliment really moved her before she and the others watch the sun rise over the horizon.