Cass and her best friends, Lex and Nicholas, are the Bubble Street Gang! They investigate crimes, solve mysteries and have brilliant adventures. They've even got their own secret clubhouse. After the annoying baby twins demolish the fort Cass has built in the sitting room, she has the great idea of building a proper fort - outdoors - that can be the Bubble Street Gang's clubhouse. Lex's granny suggests the perfect spot at the back of Mr McCall's field and Cass and the gang get to work. The gang settle in quickly and begin planning their next adventure, when they realise someone is using the clubhouse when they're not there. Stuff moves around, cookie crumbs are left behind and the door is left open. Join Cass and the Bubble Street Gang as they investigate The Clubhouse Mystery.

Coco is the shyest little mouse on Comet Island. But when his only friend Ben is captured by an owl and the island is invaded by a gang of crows, Coco must conquer his fears to rescue them both. Hatching a plan to fly to Scotland to recruit the help of a legendary golden eagle, Coco invents the Flynut - an aircraft fuelled by magical anti-gravitational skynuts. He and his intrepid team - Francesca the mouse, Batty the bat, Froggy the frog and Shimmer the flightless firefly and her forty nephews and nieces - set off on a rescue mission, crossing Scotland from Aberdeen to the Isle of Skye via Loch Ness and meeting a host of colourful characters along the way. Will Coco overcome his shyness to lead his band of merry animals? And will his fearless gang save Comet Island and rescue Ben before it's too late?

Book 4 in the Cass and the Bubble Street Gang series! Cass, Lex and Nicholas investigate crimes, solve mysteries and have brilliant adventures. They've even got their own secret clubhouse. Cass is ecstatic. Mr McCall's partner is starting a Scarecrow Festival at the McCall mansion, and it includes an all-day, mind-boggling scavenger hunt. Throughout the mansion, gardens and adjoining fields, Cass and the gang will test their wits against other scavenging teams, including Nathan Wall and the NaSaJi Club (Nathan, Sasha and Jim). But Cass isn't worried. She knows she'll win; she has detecting in her blood. But, the NaSaJi Club sabotage the Bubble Street Gang. Then, Mr Freebs has paired Cass with Nathan for a project to spruce up the gardens of a nursing home. When an elderly woman called Carmella loses her locket, Cass must put her detective skills to the test to solve the mystery of golden locket.

Book 3 in the Cass and the Bubble Street Gang series! Cass, Lex and Nicholas investigate crimes, solve mysteries and have brilliant adventures. They've even got their own secret clubhouse. Cass is not impressed with the new Residents' Association programme -- suddenly everyone's in Neighbourhood Watch and thinks they're a genius detective. And that's Cass's job!! Worse still, there are so many new rules that the kids can't even play on the street anymore. No one stops Cass and the gang from playing games - something will HAVE to be done about the Residents' Association... But there's also a mystery afoot for the Bubble Street Gang: while helping with a car boot sale, Cass finds a very old diary. The name inside the cover has worn away, but it must belong to somebody in Berbel Street. The diary talks about picking on the drama kids on the bus, and finally about a horrible prank played on them during their end-of-year show. Who does this diary belong to? Can the Bubble Street Gang unmask the wicked writer?