Tony DiNozzo's final NCIS case will have fans at the edge of their seats.

Michael Weatherly will bid farewell to the CBS series on May 17 after 13 seasons as Special Agent Anthony DiNozzo. Fans are not looking to the departure of the NCIS OG, but the actor promises upcoming finale will give him a proper send off.

"In classic NCIS style, I don't think there's enough space on your page to give you a really complete synopsis [of Tony's final episode]," Weatherly told the USA Today. "It's confusing, action-packed, incredibly emotional, unpredictable, and yet totally entertaining on both a simple and complex level."

The episode, which is titled "Family First," will see Tony's exit play out against the squads search for a missing British spy. Their target has an axe to grind with the Naval Criminal Investigative services, and his quest for revenge has already has a body count. With the help of FBI Special Agent Tess Monroe (Sarah Clarke) and MI6 Officer Clayton Reeves (Duane Henry), Gibbs' (Mark Harmon) team will work to put an end to the baddies' escapades.

"NCIS, FBI and MI6 continue an international manhunt for an escaped British spy who is targeting current and former agents," CBS teased.

What fans are really wondering, however, is what could possibly make Tony leave his work family in the wake of such a crisis?

"We started talking about it six months ago, and we knew we had to acknowledge that Michael had been part of the show since Day 1," showrunner Gary Glasberg told TV Insider. "So the episode had to show Tony in all the different ways we've come to love him. We also knew that the reason Tony DiNozzo would ever choose to leave his NCIS family would have to be something really significant. What we came up with delivers some real heart-wrenching, emotional moments."

In the meantime, catch season 13's penultimate episode, "Dead Letter," this Tuesday at 8 p.m. ET on CBS (see a preview below).

Tags: NCIS television CBS