Opening the episode with the marine’s paranoid flight into the aquarium and having his death captured on FishCam was a great jump-start for a very action-centric episode. Bringing back Special Agent Mike Renko, who appeared in the two-hour backdoor pilot that aired as part of the previous season of “NCIS,” was fun because he doesn’t distract from the main players of the team but has an entertaining rapport with the whole team and Kensi in particular.