ZIS LS Library: Grade 4 Mysteries

When Daisy Wells and Hazel Wong set up a secret detective agency at Deepdean School for Girls, they can't find a truly exciting mystery to investigate. Until they discover the body of the Science Mistress, Miss Bell - but when they return five minutes later, the body has disappeared ...

Imagines an alternate 1826 London, where Ada Lovelace (the world's first computer programmer) and Mary Shelley (author of Frankenstein) meet as girls and form a secret detective agency. Their first case involves a stolen heirloom, a false confession, and an array of fishy suspects.

Nancy, Bess, and George take an Alaskan cruise to help uncover the mystery of who is threatening the ship and its passengers

Sabrina and Daphne Grimm return to New York City to investigate the death of an important Everafter, and discover a secret that might lead them to the Scarlet Hand.

Meet Timmy Failure, the founder, president, and CEO of the best detective agency in town, probably the nation. And his lazy sidekick, Total, a 1,500-pound polar bear.

When thirteen-year-old Margaret's father is sentenced to death for a crime he didn't commit, she knows the only way to save him is to use the forbidden family power of time travel

A brutal kidnapping , a shadowy pursuer, an impossible murder -- young Sherlock Holmes: think you know him? Think again

Her grandfather's dying words lead thirteen-year-old Theodora Tenpenny to a valuable, hidden painting she fears may be stolen, but it is her search for answers in her Greenwich Village neighborhood that brings a real treasure.

Leo, the son of the maintenance man of the Whippet Hotel, opens a series of cryptic boxes which reveals hidden floors, strange puzzles, and unexpected alliances and leads him on an adventure to save the building and his future

Ben and his friend Jill find themselves in danger when they discover the secret history of their Massachusetts school and set out to derail a developer's plan to level the building to make way for an amusement park

Amy and Dan, members of the powerful Cahill family, try to uncover the thirty-nine clues which will reveal the secrets of their lineage and find out what really happened to their parents.

Joe and Frank Hardy investigate the disappearance of girl from an amusement park ride.