The Poison Garden (Unabridged‪)‬

Thomas has inherited a magical box from his dead grandmother which provides entry into a mysterious garden where her ghost warns him she was poisoned. For once she belonged to an arcane guild whose members each cultivated a garden and mastered the arts of poison, perfume and medicine. The remaining guilds members jostle for power as one by one, they are murdered. Can Thomas solve the mystery before he in turn is threatened?