It was meant to be an adventure, a night alone on a remote Irish island. Archaeologist Sophie Malone never expected to find Celtic treasure or to end up in a fight for her life in a dark, desolate cave. Now, a year later, she's convinced answers to the mysteries of that night lie in Boston. Who has the priceless gold artifacts that disappeared from the cave ... and who is responsible for the whispers she heard in the dark? Nearly killed in an explosion...

Folklorist and illustrator Keira Sullivan pursues the mysterious Irish legend of an ancient Celtic stone angel and soon becomes the target of a killer that even search-and-rescue expert Simon Cahill cannot stop.