After an operative kills all but one of the employees at a marine biology research group, McCall and the team join forces with Colton Fisk when they discover a connection between the murders and a secret CIA program he was involved in.

After a high-powered real estate developer is killed by a moving subway train, his widow hires McCall to investigate his death. Meanwhile, Aunt Vi and Dee visit an old neighbor living in a nursing home who may need their help.

McCall is contacted by Samantha Reed, whose father, ex-CIA agent Elijah Reed, is missing. While Samantha joins forces with the Equalizer team to track down the agency legend, she learns more about her family's past in the Dominican Republic.

While on a romantic getaway, McCall and Dante are abruptly ambushed by Salazar and his army. Meanwhile, Aunt Vi finally decides to take the next step in her relationship with Captain Curtis, and Dee meets with her favorite author who may be able to help her get into her dream university.