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.