Martin and Diana are stuck at school for Christmas until MOM invites them to the Center's Christmas party. All goes well, until an Evil Elf intends on ruining everyone's Christmas by twisting their Christmas wishes.
Martin is reunited with his first crush, Vivian Michelle, who embarrassed him during the grade school times. Martin tries to avoid her, but when he finds out that Vivian has changed, he changes his mind about her. Diana suspects that Vivian is different due to her strange skin. Vivian is actually Venoso, a mutated chameleon who was the first monster Martin ever caught, out for revenge.
Marvin escapes from an angry leprechaun and calls Martin and Diana for help. It turns out that he was keeping a mystic, four-leaf clover that grants the holder limitless good luck. and that leprechaun wants to take it back.
Diana resigns from the center for not having a good evaluation and joins a rival paranormal organization called the CIHL and starts stealing Martin's monsters.
Martin, Billy, and Java start their own band to attract the girls. But Martin finds out that his new electric guitar is possessed which transforms his girl fans into love monsters.
Marvin escapes an angry leprechaun and call Martin and Diana for help. it turns out that Marvin is keeping for himself a mystic four-leaf clover the grants the holder limitless good luck and the Leprechaun wants it back.
Diana is ticked off with Martin and Kaitlin, and the djini uses this to her advantage as she possesses her with an enchanted bracelet.
Billy, and Diana decide to take Martin to an amusement park for his one-year investigator reunion, but in this park the things come alive by an Egyptian spirit that thought a ride was the tomb he was guarding.
Martin goes on a school trip to a museum where there is an exhibition of pirates, and he decides to see where are the things of an old pirate that was told to have supernatural powers. Taking a medallion with him, Martin, or maybe \"Captain Blood\" now, is out to find the treasure that can raise the spirits of his crew.
A famous writer, Evan Prince, gives Martin a typewriter...without telling him that the stories Martin writes will actually come to life.
A student's plant experiment for the Science Fair goes awry and the plant starts to eat the competition and anything that gets in his way.
Martin and schoolmate Jerry are chosen to join a secret society, The Bones, where membership entails cool powers like telekenesis and free stuff like extra dessert and sports cars. Both are thrilled until they find what awaits them in their "entrance test"...
Kaitlin has fallen victim to her shadow, and as usual, it's up to Martin and Billy to save the day. They've found out that since the people who were safe slept in the light, that's the thing the shadow creatures are afraid of. With the help of the Legendex, they realize that the shadow creatures' leader, Barock the Faceless, wants to take over Earth, but needs all the humans in his realm before he can crossover—and when he does, the gateway will forever close. When Billy's gone too and Martin is the last being on Earth, the showdown begins.
Martin, Diana, and Billy are confused when one day they wake up to find themselves the only ones on campus...and the world. They soon meet Kaitlin, another confused person who turns out to be almost like Martin's clone. They find Billy after Diana disappears into a black hole, and find out that people's own shadows are attacking them and dragging them into a strange shadow world.
go with M.O.M on a six-day corporate retreat, a bad storm comes and they are forced to take shelter in a creepy old abandoned house. What they don't know is that the man who built the house is a spurned lover who still hasn't left...and doesn't want to let them leave.
Martin releases an evil warlock in order to win a competition.
A teenage girl's teddy bear turns vicious and starts turning her once-friends into doll replicas.
They find that a previous French owner used a talisman to make the farmland his own for good. The scarecrow in Martin's aunt's garden scarecrow starts to literally scare the life out of anything that trespasses.
Martin's dad accidentally releases and gets swallowed by a prehistoric worm which Martin had already caught. Worse, if he doesn't stop the worm soon, his father will become the worm forever.
Martin is scratched by a Phantom Werewolf when he cleans out the CENTER's cages. Soon, the Phantom Werewolf breaks out and begins turning other Torrington students into werewolves to serve it.
Some teens stole a lawn gnome from an old lady's garden in Ontario. The gnomes come to life and turn everyone into lawn gnomes until they get the missing gnome back.
Torrington's old biology teacher, Mr. Black, allows himself to be bitten by a spider, transforming him into a half-spider half-human creature to get revenge on the staff who forced him into retirement.
Martin orders some paranormal objects of a magazine, all result fake, except one which, when Diana breaks it, creates another Diana.
A boy decides to raise sea monkeys, but when the sea monkeys do not appear he flushes the packet down the toilet, where they reach polluted water and become sea mutants.
A boy in a town, discovers a mystery website who has trapped an evil alien that uses the energy of others to get out of his web prison.
A lonely girl at Torrington finds a mirror that makes her pretty "like the Jenni's of the world" but every boy she touches turns into a monster.
