Guest Stars Matt Craven as Secretary of the Navy Clayton Jarvis Sean Harmon as Young Gibbs Darby Stanchfield as Shannon Gibbs Jeananne Goossen as Marine Private Joan Matteson John Finn as Marine Commandant Charles T. Ellison Jaime Ray Newman as Navy Lieutenant Commander Melanie Burke Sofia Pernas as Marine First Lieutenant Gabriela Flores LaMonica Garrett as Marine Captain Craig Quincy Alex Fernandez as Joseph Flores Dylan Bruce as Justin Fanniker Samantha Sloyan as Emily Goodwin Co Starring Wade Harlan as Marine Cadence Leader