Fifteen-year-old Christine is visiting her eccentric great-aunt in historic Witcombe, where a pickpocket has been victimizing tourists. Aunt Maude owns an antique store and also runs the town’s ghost walk, which gives Christine the opportunity to meet local characters and visitors, including a mysterious young man who seems to know far too much about the crimes. When the pickpocket targets Aunt Maude’s store, Christine is determined to find out who is behind the thefts. Her search takes her through the nooks and crannies of the quaint town full of stories, and she unearths more than one surprise.
Trevor has started his first job at Ashton's Fresh Marketplace, where someone has been tampering with the food. Cayenne has been sprinkled on cookies, garlic put in coffee, and plastic insects hidden in fruit displays to terrify customers. Trevor and his friends Nick and Robyn decide to find out who is out to destroy the store's reputation. Is it Mattie, the disgruntled ex-employee? Or perhaps the competition? Or is it Alex, their schoolmate who doesn't know when a joke has gone too far? Their snooping makes the kids themselves seem suspicious, and soon they realize they have to solve the mystery before Trevor gets fired for a crime he didn't commit.
On a visit to a seaside town in Australia, fifteen-year-old Sam meets Annabel, who works at the local museum. Annabel's interest in history is infectious, and Sam soon finds himself eager to hunt for the remains of a boat called the Mahogany Ship—a shipwreck sought after by many. When a storm creates an erosion hole that exposes a structure, Sam and Annabel are convinced it's the fabled ship. Soon all of the museum staff are at the erosion site to check it out. But the same storm also destroys the museum's power; someone knows the alarms aren't working and steals the museum's most treasured artifact, a large porcelain peacock worth $4 million. As Sam and Annabel search for the thief, they realize there may be a link between the fabled shipwreck and the recent theft.
Dylan and his friends attract the attention of the police when a summer bonfire gets out of control. Dylan almost loses a job opportunity at a local inn because of his antics, but he is saved by the lies of Heather, an employee of the inn. When he is caught on camera stealing towels from a summer cottage after a skinny-dipping prank, Dylan and his friends become suspects in a number of cottage robberies. Dylan learns everything he can about the robberies, with the hope of clearing his name, and finds himself in more than one sticky situation in the process.
Chloe McBride has some reservations about accepting her elderly great-aunts' invitation to spend part of the summer with them in Little Venice, but her initial reluctance is outweighed by her curiosity about the mysterious key that came with her aunts' note. She's also anxious to put the humiliating memory of a disastrous piano recital as far behind her as possible. Chloe's great-aunts tell her the legend of her great-grandfather, Dante Magnus, an ambitious magician who vanished without a trace almost a century earlier, and Chloe begins to search for clues to his disappearance. When her investigations eventually lead her to a mysterious rosewood box, which has been hidden for almost a hundred years, Chloe's belief in the power of magic forces her to confront her own fears and ambitions.
Sam Stringbini, the youngest son in a family of circus performers, is living every kid's dream, except for the fact that he is no good on the high wire, trapezes freak him out and magic mystifies him. When the Triple Top Circus is threatened by repeated acts of sabotage, Sam is the number one suspect. To clear his name, Sam enlists the help of his cousin, Harriet, and discovers that, while he may never be a sword-swallower or a lion-tamer, he just might be able to save the circus.
With seconds to the finish line, Dalen and Gole lead the distant world of Budap's annual Junior-Jet Race. Suddenly they are overtaken. Left behind in a cloud of mysterious purple exhaust, they realize something doesn't add up. Looking for clues, the two friends uncover a tunnel that leads them to Earth. They arrive in Port Angus, once a lively west coast fishing community. The fishing industry is dying, and Dalen and Gole find themselves embroiled in a sinister plot to steal fish and send them to Budap. Pursued by government agents and angry aliens, Dalen and Gole are in a race against time to save both their own distant world and the fishing community of Port Angus.
Zack Freedman has complete control and feels a sense of calm on the high wire. If only he could say the same about the rest of his life. His fellow youth circus performer and roommate, Cubby, hates him, and his aunt dumps a yappy, excitable dog on him. When a necklace is stolen during a circus performance and the victim of the theft threatens to shut down the circus, Zack is desperate to solve the mystery so he can keep his place on the wire.
Clay would much rather work as a lifeguard at the beach than at Safari Splash, the new water park in town. He's certain the summer will drag along, despite his position at the Boa, the park's fastest slide. The summer job starts to get interesting when he learns that someone has been wandering the park in a lynx costume, scaring the staff. When forty thousand dollars is stolen from the till, and his friends are under suspicion for the theft, boring is starting to look good. But Clay is certain that the mask and the thefts are connected, and he's determined to solve the crime.
While volunteering at the local zoo, Robyn, Nick and Trevor learn that grizzly bears are being poached and their gall bladders removed for use in alternative medicine. Always ready to solve a mystery, the kids set out to find the poachers. Bear is not only big game, they learn, but big money to poachers. The stakes are high and the suspects many, as the kids head into their most dangerous adventure yet.
When Trevor, Nick and Robyn visit the Royal Tyrrell Museum, Robyn is inspired to raise funds for a dinosaur dig that will close soon if it doesn't find funding. The kids are caught up in another mystery when a chain of suspicious events, including the disappearance of important fossils and a fraudulent discovery at the dig, leads them to wonder what's going on. Is the new visiting scientist behind the fraud, or did Robyn's enthusiasm to save the dig lead her astray?
Trevor, Nick and Robyn are ready to solve another mystery. When bobsledder Josh Gantz is accused of deliberately injuring a fellow competitor, he runs the risk of being thrown out of the sport -- right before the World Cup. Courtney Gantz asks Trevor, Nick and Robyn to help clear her brother's name. Can they find out who framed Josh? What is the meaning of the strange coded messages they keep finding around Olympic Park? Who eats orange bananas, anyway? The kids must unearth the clues in a race against time, before Josh's championship dreams end up on ice.
Angus and his best buddy, Shahid, share a love of science and their robot, Gordon. But recently, the artistic Ella Eckles has had a peculiar effect on Angus. When a stink bomb at the school provides a chance for him to talk to her, he claims to share her interest in reading facial expressions and declares his ambition to become a crime-solving mentalist. He impresses Ella by identifying the stink bomber, but fails to mention he witnessed a scrawny kid setting off the bomb. When Ella's treasured sketchbook is stolen, she asks Angus to find the thief. Shahid thinks Angus should confess that he's not a mentalist, but Angus is certain he can learn to read people and recover Ella's sketchbook. He asks Shahid to help him investigate the suspects: Gaga Girl; the art teacher, Mr. Wilder; and finally, "scrawny kid." Equipped with rearview sunglasses and an informant who lurks in the washroom, the duo bungles their way through a series of encounters that alarm Shahid and provide Angus with some unfamiliar exercise.