After 18 seasons and 392 episodes, Leon Vance has left NCIS - this time through heaven's door. The long-running CBS crime drama stunned fans by killing off Vance, portrayed by Rocky Carroll, in the series' benchmark 500th episode on March 24. The emotional episode also featured an imagined reunion with a younger version of his late colleague, Chief Medical Examiner Donald "Ducky" Mallard (Adam Campbell). Ducky, bow tie and all, guides Vance into heaven, glowing ethereally behind the door to the director's assistant's office.