It's Walker's birthday, and Geri is pulling out all the stops, but her plans are thwarted. Walker, Captain James, and Trey tackle a case together, and Cassie surprises everyone with her return. Abby asks for Liam's help to bring Stella out of her cocoon. Meanwhile, August is enjoying his senior year of high school, leaving Walker feeling like an empty nester.

When Maybelline, an 80-year-old grandmother and witness, is in crucial need of protective custody, Walker, Cassie and Trey are charged with keeping the acerbic matriarch safe, and though Walker and crew call the plays, the wise elder is the one keeping score. Cassie grapples with a big decision and asks Geri for help to make some changes. Meanwhile, Stella wants to move on but continues to struggle with her grief and Liam tries to help. Lastly, August wants to join an after-school program and asks Bonham to help convince Walker to sign off on the program.

Trey and Liam try to help Walker figure out his next steps with Geri. Liam confides in Walker that he's worried about Stella. Meanwhile, Stella and Sadie look into recent events. August begins his bootcamp training and it is not what he expected. Liam helps Cassie sift through the clutter. Lastly, the family works together on a fundraiser.

Walker's lies about the Jackal case finally catch up to him, testing his friendship with his old partner, Captain James. Cassie works a lead in the Jackal case alongside Detective Luna and learns a hard lesson. Stella makes a shocking realization.

Walker, Trey, Cassie and Detective Luna are all hands on deck with their case. Geri is presented with an interesting offer, and Liam jumps in to help. Meanwhile, Stella and August help Abby and Bonham and stumble upon some interesting information. Lastly, James tries to make amends.

Walker, Trey and Cassie prepare for what Captain James has in store for them at HQ. Meanwhile, Stella and August start to put some pieces together. Lastly, Walker makes plans for his future and Liam questions his brother's motives.

Walker, Trey, Cassie and Detective Luna explore more leads as Walker starts to become more and more invested. Captain James notices Casey and Luna growing closer. Stella goes to Bonham for self-defense training and August excels in his boot camp training. Lastly, Bonham and Abby discuss the future with mixed opinions.

Liam express his concerns about Walker to Trey. Walker becomes more invested in the case as Captain James asks him to take a break. Stella continues her search for the necklace and starts putting together the pieces of the mystery. August goes to his dad for help with a school project. Meanwhile, Cassie and Detective Luna take their relationship to the next level.

Geri discussed her new business venture with Walker, but there is more to her return. James, Cassie and Trey appear to make some headway in their investigation. Meanwhile, Stella and August make a startling discovery. Lastly, Bonham and Abby have differing views about their retirement plans, with Liam serving as a referee.

Walker sets out on a mission. August opens up to Geri and Liam. Bonham notices something is off with Abby. Luna introduces Cassie to an old friend.

Cassie, James, Trey and Luna start to put together the pieces of the Jackal case, while no one has heard from Walker.

Geri is upset with Walker for not opening up to her. Cassie, Trey and James conduct more interviews. Bonham and Abby realize they both need to give a little with their plans for the future.

Walker tries to make up for lost time and wants to be what Geri deserves. Cassie and Trey have their final interviews for the lieutenant position. Stella discusses with Liam what she may want for her future.