"NCIS: Origins" did not need to look far for the perfect actor to play young Donald "Ducky" Mallard in a Season 2 tribute to David McCallum, who portrayed the eccentric medical examiner on the flagship "NCIS" for 20 seasons. British actor Adam Campbell ...

This will be Stowell’s first episode working with Campbell; the actor played young Ducky in four NCIS episodes, and on the mothership, young Gibbs was played by Sean Harmon (who is an exec producer on Origins ). “Ducky is undeniably charming, able to win over the grumpiest of grumps,” notes Stowell.