Coming up on the season finale of Without a Trace:

"Crossroads" -- While investigating the disappearance of a young female former assistant district attorney, Jack and the rest of the team are blindsided when the woman's ex-boyfriend suddenly opens fire on the FBI offices, on Thursday, May 18, on CBS.

Academy Award nominee and Tony Award nominee Mary Elizabeth Mastrantonio returns as Jack's girlfriend and colleague, FBI agent Anne Cassidy. Jason Priestley guest stars as the suspect.

When Alan Davis (Priestley), the former boyfriend of the missing Jennifer Nichols, realizes that he's a suspect in her disappearance, he suddenly pummels Jack, grabs Jack's gun and bolts out of the FBI building while firing a hail of bullets. Before and after the shooting, Jack and the team delve into Alan's background and possible motives while also looking into the relevance of Jennifer's mysterious visit to a prisoner the night before she vanished.