When their grandmother comes crashing back into their lives, twins Tilly and Tom know their twelfth birthday will be anything but ordinary. The twins are left with a mysterious gift and a warning, it must not be opened before midnight. But in a house where shadows have eyes and dinner guests harbour dark secrets, following their Grandmother's rules might prove harder than expected. They are about to discover that their Grandmother's magical stories might not be so fantastical after all. As ancient family secrets begin to surface, the twins discover that some gifts come with a price—and some doors, once opened, can never be closed again. Embark on a spellbinding adventure into other realms where anything is possible, as Tilly and Tom uncover their family's secret legacy, forbidden magic, and find the courage to face the unknown when darkness comes calling.