The Mystery of the Headless HaunterAddison has to solve the mystery of what's making scary sounds after Donnie convinces the other kids on an Ayrton Rangers camping trip that a mythical spook is wandering through the park.
The Mystery of the Maleficient Mosquitoes
E2
The Mystery of the Maleficient MosquitoesWhen swarms of mosquitoes mysteriously descend on the park, the kids' summer movie night is in danger of being cancelled unless Addison and her friends can figure out a way to stop them.
The Case of the Curious Coin
E3
The Case of the Curious CoinAddison and Alex dig up what they think is an Ancient Roman coin in the community garden - then have a mystery to solve when it unexpectedly disappears.
Scooped!
E4
Scooped!When Addison and her classmates get a school assignment to write about local news - and the news is that laundry is going missing from balconies around Ayrton Park.
The Mystery of the Robot Rivalry
E5
The Mystery of the Robot RivalryAddison's excitement at bringing Eureka and Gyro in for a show and tell at school turns to consternation when Donnie turns up with a robot that can do everything hers can do - only better!
The Mystery of the Reluctant Racer
E6
The Mystery of the Reluctant RacerAddison and Alex's record-setting soap box derby car seems like a shoe-in to win the annual race - until something or someone makes it mysteriously slow down to a crawl.
The Mystery of the Ghostly Go Kart
E7
The Mystery of the Ghostly Go KartWhen Kevin's new radio-controlled model car starts acting like it has a bad-tempered mind of its own, he becomes convinced that it is haunted and asks Addison to help.
The Mystery of the Party Popper
E8
The Mystery of the Party PopperWhen helium balloons for Tess's fashion show start inexplicably popping, she is upset and asks Addison to help her figure out the cause and stop the rest of the balloons from popping before.
The Recycling Bandit
E9
The Recycling BanditAddison and her friends are distracted from their mission of making cool costumes for Ayrton Park's version of Comicon when someone or something starts messing with recycling bins.
The Mystery of the Missing Pteranodon
E10
The Mystery of the Missing PteranodonWhen an inflatable Pteranodon goes missing from the roof of Pizzamat, Addison and Alex are on the case to find it.
The Mystery of the Shrinking Rink
E11
The Mystery of the Shrinking RinkAddison’s plans for a local version of the winter Olympics are in jeopardy unless she can figure out why their outdoor ice skating rink keeps mysteriously melting and running away.
Mystery of the Birthday Brainteaser
E12
Mystery of the Birthday BrainteaserAddison fears that her family and friends have forgotten her birthday, so instead takes consolation in trying to solve a series of mysterious clues that take her on a wild goose chase.
The Mystery of the Halloween Haunting
E13
The Mystery of the Halloween HauntingAddison and Tess make a haunted maze for Halloween, but things take a perplexing turn when it seems that there really is a spooky presence on the loose within it.
Mystery of the Runaway Robots
E14
Mystery of the Runaway RobotsAddison is stumped when she awakens one morning to discover that Eureka and Gyro have disappeared without explanation!
The Case of the Curiously Missing Kitty
E15
The Case of the Curiously Missing KittyWhen Mr. Tiggles goes missing, Addison must figure out if this is just a matter of a cat stuck in a tree, or a nefarious kitty kidnapping conspiracy.
Mystery of the Sneezy Snuffle-ies
E16
Mystery of the Sneezy Snuffle-iesWhen Mrs. Rorschach suddenly develops an allergy, every indicator points to Mr. Tiggles as the cause. Addison has to solve the mystery.
The Missing Mammoth
E17
The Missing MammothMs. Bell has planned to surprise her students by hiding mammoth fossils in the school sandpit for them to dig up. But the surprise is on Ms. Bell and her students when the fossils disappear.
The Mystery of the Suspicious Circle
E18
The Mystery of the Suspicious CircleWhen crop circles begin appearing in Ayrton Park, Alex suspects visitors from the fourth dimension, but Addison begins sleuthing in search of a different explanation.
The Mystery of the Hidden Gem
E19
The Mystery of the Hidden GemWhen Addison and Tess find a note in a funny old pair of rummage sale pants, they think they may have found a clue to lead them to a stash of priceless hidden diamonds!
The Mystery of the Mean Girls Detective Agency
E20
The Mystery of the Mean Girls Detective AgencyWhen the school mean girls, Katie and Dinara, start their own detective agency and solve a rash of neighbourhood mysteries before Addison can, she wonders if she's lost her touch.
The Musical Mystery
E21
The Musical MysteryAddison and her classmates are tasked with playing a piece of music written by the local eccentric billionaire, who has promised to donate much-needed funding to the school's music program.
The Mystery of the Fairy Frog
E22
The Mystery of the Fairy FrogAddison's and Tess's fairy garden school project attracts a mysterious glowing frog, and while Alex thinks it's radioactive and Tess believes it's a magical fairy frog.
The Not-So-Fishy Mystery
E23
The Not-So-Fishy MysteryWhen the fish in the local pond all seem to disappear, Addison and Tess fear that they ended up as fish sticks in the school cafeteria's lunch special and set out to solve the mystery.
The Mystery of the Lucha Grandma
E24
The Mystery of the Lucha GrandmaAddison and Alex are afraid that Mrs. Rorschach is being secretly intimidated by a shadowy pro wrestler named the Lucha Grandma and are determined to find out her identity and put a stop to her antics.
The Secret Admirer Mystery
E25
The Secret Admirer MysteryWhen Alex receives an unsigned note from a "secret admirer", he calls on Addison to help him find out who thinks he's so wonderful!
The Midnight Ninja Mystery
E26
The Midnight Ninja MysteryWhen it appears that a midnight vandal is damaging Max's entry in the town's "Most Beautiful Public Garden" project, Addison goes undercover ninja to save the day.
The Mysterious Bleeps and Bloops
E27
The Mysterious Bleeps and BloopsMysterious cyber events begin happening around town and Addison wonders if the occurrences could be part of a world-wide-web... of mystery!
The Perplexing Parrot Mystery
E28
The Perplexing Parrot MysteryWhen a lost parrot appears in Ayrton Park, Addison must find some way of returning it to its rightful owner by deciphering clues from the cryptic phrases that the errant bird utters.
The Fog Mystery
E29
The Fog MysteryAddison and Alex are filming a class-project documentary about a "typical day in Ayrton Park."
The Double Mystery
E30
The Double MysteryAddison is faced with a double challenge: figuring out who is behind a series of very strange thefts in Ayrton Park, and then when she does discover who the perpetrator is.
