"When Hyacinth mixes hot and cold water in a sink in London with disastrous results, she learns that the city was built on magical rivers that are now London's sewers--and somehow her family is connected to the magic"--
"When Hyacinth Hayward tries to learn more about the magical rivers under London and how her family is connected to them, she stumbles upon a plot to steal the ancient stones that hold the city together"--
