Martin Mystery - Season 3 (2005)

Torrington's old biology teacher, Mr. Black, allows himself to be bitten by a spider, transforming into a half-spider, half-human creature to get revenge on the staff who forced him into retirement. The spider is really a spitting spider, which is why Mr. Black was able to fire a web thread from his mouth.

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.

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.

Martin is scratched by the Phantom Werewolf when he cleans the Center's cages. Soon afterwards, the Phantom Werewolf escapes and turns Torrington's students into werewolves.

Martin's dad accidentally releases and is swallowed by a prehistoric worm, which Martin caught. What's worse, if Martin does not stop the worm soon, his father's and the worm's DNA will become merged forever.

Martin releases an evil warlock in order to win a competition.

An Ontario teenage girl's teddy bear turns vicious, and starts turning her friends into doll replicas.

Martin, Diana, and Java visit Martin's aunt but discover the farmland's secret. It seems that a previous French owner used a talisman to make his farmland his own for good. Up to now, the scarecrow in Martin's aunt's garden, starts to literally scare the life out of anything that is trespassing.

When Martin, Diana, Java, and Billy go with M.O.M. on a six-day corporate retreat, a bad storm comes up and they are forced to take shelter in a creepy old abandoned house. What they do not know is that the man who built the house is a spurned lover who still has not left ... and does not want to let them leave. This episode is an homage (or remake) of Sam Raimi's The Evil Dead.

Martin and schoolmate Jerry are chosen to join The Bones, a secret society where membership includes cool powers like telekinesis, and free stuff like extra dessert, and sports cars. Both are thrilled until they find what awaits them with the "entrance test".

Martin, Diana, and Billy are confused when they wake one day to find themselves the only ones on campus and what appears to be the world. They soon meet Kaitlin, another confused person who turns out to be almost like Martin's kindred spirit. They find Billy after Diana disappears into a black hole, and discover that people's own shadows are attacking them, and dragging them into a strange shadow world.

Kaitlin has fallen victim to her shadow and, as usual, it is up to Martin and Billy to save the day. They have found out that since the people who were safe slept in the light, that is the thing that the shadow creatures fear. With the help of the Legendex, they realize that the shadow creatures' leader, Barok the Faceless One, wants to take over the Earth, but needs all the humans in his realm before he can cross over--and when he does, the gateway will close forever. When Billy is also taken, and Martin is the last being on Earth, the showdown begins.

Diana is ticked off with Martin and Kaitlin, and the Djini uses this to her advantage as she possesses her with an enchanted bracelet. The Djini is after revenge as she uses Diana to tempt Billy, Java, and Martin into her enchantment to get free.

A famous writer, Evan Prince (Stephen King), gives Martin a typewriter without telling him that the stories Martin writes will actually come to life.

Martin and Diana are stuck at school for Christmas until M.O.M. invites them to the Center's Christmas party. All goes well until an evil elf appears, intent on ruining everyone's Christmas by twisting their Christmas wishes.

Martin is reunited with his first crush, Vivian Michelle, who embarrassed him during 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.

M.O.M, Java, Billy, and Diana decide to take Martin to an amusement park for his one-year investigator reunion, but when Billy goes missing, the gang decides to look for him. M.O.M. and Java are turned into zombies, and Diana is turned into a two-headed sea serpent. Martin soon learns that the park is being haunted by an Egyptian spirit.

Martin, Billy, and Java start their own band to attract girls, but Martin finds out that his new electric guitar is enchanted and transforms his girl fans into love monsters.

A student's plant experiment for the science fair goes awry and the plant starts to eat the competition--and anything else that gets in its way.

Martin goes on a school trip to a museum where there is an exhibition about pirates. He decides to see where the things, said to have supernatural powers, belonging to an old pirate are located. Taking a medallion with him, Martin, or more like "Captain Blood," puts Java and his teacher under his spell, and is out to find the treasure that can raise the spirits of fallen pirates.

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 being given a good evaluation and joins a rival paranormal organization called the CIHL "presented to her as the Creative Institute for Higher Learning - a cover-up name". Unbeknownst to her, there is an ulterior motive behind their invitation. Now armed with CIHL gear, she starts stealing Martin's monster caches.

Diana learns that CIHL stands for "Creature Intelligence Hybrid Laboratory" and starts to fight against it. However, she is overpowered by monsters who were once Octavia Paine's agents "Octavia Paine just used her". She was turned into a half-lizard, half-girl hybrid by Octavia Paine, a former Center agent, who also did not get a good evaluation. Then Octavia creates the "Ultimate monster" from the stolen monsters and sends it to get revenge on M.O.M. Martin and Diana work as a team to defeat it. In the end, Diana gets an upgraded evaluation, while Martin gets a ...