In this third book in the series, Harley goes on a time-twisting adventure! On a school trip to the Inventia Jurassic Coast, Harley finds an unusual fossil. Has she discovered an entirely new species of dinosaur? Her class nemesis, Fenelda, doesn’t believe it, so Harley decides to build a time machine to prove the discovery and win the ‘best invention’ competition. But messing around with time can have unexpected, dinosaur-size effects…

Vashti Hardy’s immersive world building, cool science and tech, weird and wonderful inventions, warm and funny characters – all perfectly pitched for younger readers. A modern-day INSPECTOR GADGET meets THE WORST WITCH, with a STEM twist.