Jess sacrifices everything to confront her dad’s killer to find the last piece of the map. But that meeting rocks her world as she learns that nothing is what’s expected on a treasure hunt, propelling her to make a dangerous decision that could land her in prison for life.

It's a matter of life and death when Jess and her friends embark on their most impossible caper yet. Meanwhile, Liam teams up with his grandpa's home care nurse, Myles, in a desperate attempt to bring down Billie and her secret organization before they harm Jess.

After getting captured by Billie, all hope of saving the treasure seems lost for Jess. Tasha, Oren, Ethan, and Liam try to track Jess down using Tasha's tech skills. Meanwhile, Liam finds a hidden cypher left behind by his grandpa, which holds the truth about Billie and the mysterious Salazar.

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.