Origins episode “The Edge” are ahead! NCIS: Origins Season 2’s third episode shed a lot of light on Dr. Donald “Ducky” Mallard, like why he talks to bodies, why he calls Leroy Jethro Gibbs by his middle name,

Harmon will return in the flesh for a special crossover event on Tuesday, Nov. 11. For one night only, “NCIS” and “NCIS: Origins” are swapping time slots; the spinoff will air first at 8 p.m. ET, followed by the original series.

NCIS: Origins revealed more of the backstory of Special Agent Leroy Gibbs ( Austin Stowell) and NIS medical examiner Dr. Donald “Ducky” Mallard ( Adam Campbell) on tonight’s episode, and it was a surprise how much Gibbs’ friendship meant to Ducky and how little of it Gibbs remembered.

But arguably the biggest reveal came with learning why Ducky talks to bodies, which we saw the late David McCallum did when he was playing him for so many years on NCIS. Origins co-showrunner Gina Lucita Monreal and Campbell opened up to CinemaBlend about telling this “difficult” story and more.

Origins would deliver its own tribute to fan-favorite Donald “Ducky” Mallard, it was hard to know what to expect from this venture or whether Adam Campbell could reprise the role in a way that aligned with this spinoff.

Origins season 2 depicted how the characters are suffering in their own way in their personal lives. There is a distinct level of authenticity to their storylines.

Gibbs (Austin Stowell) and Ducky Mallard (Adam Campbell) already have a personal history together, which is why Ducky's called in as a liaison between Gibbs' people at Camp Pendleton and the D.C. NCIS office — and also why Ducky gifts Gibbs upon their parting with a special object that they both admired while out on the town together: a boat in a glass bottle.