Warning! Spoiler alert for NCIS: Origins episode 17.NCIS: Origins has already shed a lot of light on Gibbs' life, but episode 17 explains one of his worst decisions in NCIS. The NCIS spinoff has largely followed Gibbs' life in the aftermath of losing his wife and daughter in a terrible incident. The show has also tried its best to follow NCIS canon, which makes some of Gibbs' actions in the prequel even worse since there is now even more context for why Gibbs is the way he is in the flagship.