An action thriller, DIG tells the story of a murder mystery set against the backdrop of modern day Jerusalem, a city shrouded in ancient intrigue. FBI agent Peter Connelly has had his fair share of heartbreak. Anxious to leave his personal demons behind, Peter takes a job stationed in Israel under the guidance of his new boss, and occasional lover, Lynn Monahan. When he sets out to solve the murder of a young American, Peter soon finds himself embroiled in an international mystery that delves into the Holy Land's darkest secrets. What he discovers is a conspiracy thousands of years in-the-making that threatens to change the course of history. While Peter races to figure out what it all means, he quickly finds that he may not be the only one searching for answers.
Peter continues his personal quest to find the murderer of a young American while also pursuing the escaped Yussef Khalid. Peter and Detective Golan Cohen forge an uneasy alliance as Peter grapples with staying one step ahead of his partner. Elsewhere, Avram's journey with the red heifer to Israel encounters a dangerous road block. Meanwhile, Tad Billingham and his disciples prepare Josh for a new life and an event that could alter the fate of the world.
Forget what you think you know, because everything is about to change. As Golan arrests Emma's suspected killer, Peter makes a startling discovery. In Croatia, Avram and the red heifer are kidnapped by a stranger with a mysterious agenda. In New Mexico, Tad Billingham desperately tries to keep Debbie and Josh from exposing his secrets.
After Peter has a startling breakthrough in the Emma Wilson case, he turns to Golan to search out new clues. A furious Ambassador Ridell pressures Lynn to get Peter out of the country. In the New Mexican dessert, Debbie must make a dangerous trade with Tad Billingham if she wants to spare bloodshed. Rabbi Lev and a new partner work deep in the underground tunnels to carry out their mission.
With her job on the line because of Peter's disruptive behavior, Lynn suspects a possible mole in her midst at the consulate. Meanwhile Margrove and Peter both head to a convent with very different goals in mind. With nowhere else to turn and unable to trust anyone, Debbie returns to the compound seeking vengeance.
An ancient religious sect completes all of the pieces to enact their deadly plans. Peter's attempt at preventing the impending catastrophe thrusts him into partnership with unlikely allies. Lynn realizes the depth of the conspiracy during her investigation into Ambassador Ridell, who is expecting a package from the States. Meanwhile, Golan tries to crack more clues from the Donaldson case. An emboldened Avram realizes what needs to be done and makes a move to protect his valuable asset.
With the fate of humanity at stake, Peter races to stop the Order of Moriah's plan to destroy the Temple Mount and bring about the End of Days. A trapped Lynn takes matters into her own hands, leading up to an explosive confrontation with the Ambassador. Tad Billingham is confronted by a deadly flaw in his plan. Peter discovers all of the answers in the Emma Wilson case.