With their friend kidnapped by a rival treasure hunter, Jess and her best friend, Tasha, hatch an elaborate plan to get him back, leading to a ransom exchange on a WWII warship, where Jess realizes this treasure hunt is too dangerous to continue. But will all that change when Liam Sadusky lets her in on one of his own family secrets?

With his identity finally revealed, Salazar joins Billie in the final leg of the treasure hunt, where Jess and her allies try to outwit Billie using Jess’s knowledge of puzzles and history to escape and protect the treasure.