NCIS Episode 500 Is A Sequel To A Classic Season 1 Episode

Contains spoilers for "NCIS" Season 23, Episode 13 — "All Good Things"

"NCIS" is already one of the longest-running shows in history, but it recently hit a landmark that puts it in truly rarefied air: 500 episodes. Showrunners saw to it that the episode, titled "All Good Things," wasn't just a regular ol' "NCIS" entry. In addition to the shocking death of a character that had been around for 18 seasons, the episode also marked the occasion by following up on a plot thread that goes all the way back to the second-ever episode of the series.

Season 1, Episode 2, titled "Hung Out to Dry," sees a Marine killed as the result of a parachuting mishap during a training exercise. It is eventually discovered that the Marine's death was no accident and that he was in fact murdered. Sadly, he is survived by a young son, Billy Fuentes (Austin Marques), who Gibbs (Mark Harmon) promises will always have the help of NCIS should he need it. And though one of Gibbs' rules on "NCIS" is to not get personally involved in cases, the episode ends with him finishing the treehouse that Billy's father started.

Which brings us to "All Good Things," and the surprise return of Billy Fuentes for the first time since that episode. He first comes to Nick Torres (Wilmer Valderrama), who doesn't recognize Billy — he wasn't around at the time — but Billy says he's heard a lot about Torres. He then tells Torres about Gibbs' promise to him, and explains that he now needs the help he was offered all those years ago. 

Given that we hadn't seen Billy Fuentes in 23 years, any actor could've been brought in to portray his adult version and nobody would've known the difference. Seeing as the original actor, Austin Marques, was apparently among the ranks of child stars who wound up with normal jobs as grown ups (his screen credits end after 2007), it would be easy to assume that he didn't return to play Billy again. However, that assumption would be incorrect.

As confirmed by showrunner and executive producer Steven D. Binder, Billy was indeed played by Marques once again: The casting department "got the same actor, which was great," Binder gushed to the Los Angeles Times. Indeed, Marques is one of those adults who still closely resembles his child self, so it definitely lands well that they got him back — especially given that the episode includes a flashback to "Hung Out to Dry" that prominently features shots of his original appearance as Billy.