Siblings Amy and Dan must find another way to outwit the Vespers when they target and kidnap Dan's only friend, eleven-year-old Atticus.

Cahills are being kidnapped by a shadowy group known only as the Vespers. Now Amy and Dan have only days to fulfill a bizarre ransom request or their captured friends will start dying. Amy and Dan don't know what the Vespers want or how to stop them. Only one thing is clear. The Vespers are playing to win, and if they get their hands on the Clues ... the world will be their next hostage.

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....

"When seven members of their family were kidnapped, thirteen-year-old Dan Cahill and his older sister, Amy, got ready for the fight of their lives. But their enemy, a terrifying group known as the Vespers, remained frustratingly elusive. They stayed in the shadows, picking off Cahills one by one. And now the Vespers have landed their most serious blow yet--a blow that strikes at the very heart of the Cahill family. Because Amy and Dan discover that...

From New York Times Bestselling author and Queen of Suspense, Lisa Jackson, comes If Only She Knew, a novel that will having you holding your breath as you turn each page. Perfect for readers of The Silent Patient and Then She was Gone!

If She Only Knew, introduces the Cahills, a wealthy San Francisco family—rich in money, twisted secrets, and hidden agendas. Now at the center...