As the Summer Solstice approaches, celestial magic is afoot in Myrtlewood... Rosemary and Athena's lives are thrown as the big Summer Solstice festival brings a series of mysterious events. Rosemary's chocolate shop plans are being waylaid by strange disappearances and uninvited visitors. Meanwhile, Athena is sure the astrological lessons at Myrtlewood Academy hold the key to unlocking the town's latest mystery, even if her mother doesn't want to hear about it. Can Rosemary and Athena manage to work together and cast aside their stubbornness before thousands of festival-goers succumb to a magical catastrophe?