Meggy arrives in London expecting to be welcomed by her father, who sent for her, but he doesn't want her to assist in his laboratory when he sees that not only is she female, she needs two sticks to walk. Sent on trivial errands, she learns to navigate the city, which is earthy and colorful as well as dirty, noisy, and filled with rogues and thieves. Meanwhile she is befriended by the alchemist's former assistant, and when it appears that her father may be arrested and beheaded for practicing magic, together she and her new friend devise a plan to save him. Building strength and street smarts, Meggy goes from helpless to confident and from friendless to surrounded by warmth and love. Elizabethan London has its dark side, but it also has much to offer Meggy Swann.