Pearl and Vally Cole live in a bookshop. And not just any bookshop. In 1893, Cole's Book Arcade in Melbourne isthe grandest bookshop in the world, brimming with every curiosity imaginable. Each day brings fresh delights forthe siblings: voice-changing sweets, talking parrots, a new story written just for them by their eccentric father.When Pearl and Vally learn that Pa has risked the Arcade – and himself – in a shocking deal with the mysteriousObscurosmith, the siblings hatch a plan. Soon they are swept into a dangerous game with impossibly high stakes:defeat seven challenges by the stroke of midnight and both the Arcade and their father will be restored. But if theyfail Pearl and Vally won't just lose Pa – they'll forget that he and the Arcade ever existed.