A Confederate general's threat to burn Hagerstown, Maryland, unless its citizens pay him an exorbitant ransom, prompts twelve-year-old Amelia and her friend to find some way to save their community.

In 22nd-century Great Britain, where climate change has caused vast flooding, the piratical Reavers kidnap the Prime Minister's daughter and thirteen-year-old Lilly Melkun, an English fisher-girl, takes her seacat on a daring rescue attempt, with a mysterious talking jewel from a past computer age tucked in her belt as ransom.

"It started with a kidnapping. A shadowy organization known only as the Vespers snatched seven members of the Cahill family and demanded a series of bizarre ransoms from around the world. Thirteen-year-old Dan Cahill and his older sister Amy began a global treasure hunt, determined to bring back whatever Vesper One needed, so long as it kept the hostages safe. But when they deliver the last ransom, Amy and Dan discover Vesper One's terrifying endgame....