The team investigates a millionaire whose wife has disappeared, and who is suspected of killing her. On the personal front, Angela goes to visit her father in prison for the first time in over ten years, but still has trouble letting her guard down about her past with her new boyfriend.

The team tries to derail a father-and-son crime team's plan to rob a sports arena. Meanwhile, Angela finds out that her dying mother could survive if she gets a bone-marrow transplant.

Angela goes undercover as a high school substitute teacher to investigate a series of drug overdoses among the students. Meanwhile, she struggles to make sense of a secret meeting she witnessed between her boss and her imprisoned mother.

Leo is particularly affected by the unit's search for a missing girl. Meanwhile, Angela discovers more about the relationship between her mother and her boss.

Angela arranges for her brother Jerry to meet her boyfriend Dylan, but things are interrupted by a shooting involving an unexpected visitor from her past. Leo and Dozer hunt for the gunman with their only clue being the code word "bluebird," a reference to her first case with the FBI. Meanwhile, flashbacks reveal how Angela was recruited to join the bureau.

Investigating the murder of an old friend of Leo's who was working undercover, Angela suspects that the man was a dishonest cop. Meanwhile, she has to decide what to do in her relationship with Dylan, who has disappeared.