The episode that changes everything well at least character wise. Schanke and the captain die in a plane due to a bomb planted by a bomber. His plan was to give it to his slutty girlfriend. She opens the box in midair and then boom.
Schanke's death was necessary I guess for the story but Janette's disappearence from the show was a lot harder to swallow. She was Nick's big love aside from Natalie, and yet she just walked away from the man she shared so many intimate moments? Not bloody likely.
This leads to the introduction of Tracy Vetter and Vachon, not too mention the suck up kiss butt new boss. Man these characters were horrible. Tracy started to grow on me but Vachon and the new captain brought nothing new to the show. THe writers were trying to create another love triangle with Vachon and Tracy but we already had that with Nick, Janette and Natalie so this was totally unnecessary. As it stands then it's probably the worst episode of Season Three next to the finale. The episode after this would be better as Nick would get back to form and rekindle his love with Natalie. The classic flashbacks would still be there.
In short, while there were a lot of rotten changes in Season Three there were many great episodes after this until the final show.