But I am still disgruntled. I am disgruntled because last season, Zack Addy, cute and sweet and socially maladjusted and logical and brilliant Zack Addy, was outed as being an idiot who was helping a crazed serial killer murder people and then eat the flesh from their bones with one sick set of dentures. Zack, due to being locked up for his part in the crime spree and having much of his hands decimated by a lab explosion he himself set up, will not be back this season in the lab. Oh, there are plans to visit him Hannibal Lecter style, but the joy is gone; the magic of Zack Addy has been destroyed for a subpar season finale.
Why doesn't Zack's outing make sense, do you ask? Well, that's fairly simple. Dr. Zack Addy is an incredibly logical being. And while the entirely rational mind can be a dangerous thing, Dr. Addy doesn't have an entirely rational mind -only a mostly rational one. And for him to be convinced that killing certain people would better save the world when there has been no evidence that Gormogon -a series of serial killers all belonging to the same anti-Masonic order- had done anything to make society better was ridiculous. Equally ridiculous was for Zack Addy to believe that only "widow's sons" -the serial killer's preferred victims- deserved to die for their sins. Even barring Zack's ability to see good and evil in this, there is the fact that Gormogon attacked Dr. Brennan and Agent Booth with a bomb of bones that could have easily killed them. Since Zack practically hero-worships both Brennan and Booth, it would be highly unlikely he would then earnestly and willingly help the person who tried to kill them. Dr. Addy was someone who wanted to solve crimes, to put the bad guy away. He was also rational enough to understand that joining up with a serial killer would place the authenticity of his work -and those of his friends' and colleagues' work- in incredible jeopardy and could possibly lose the Jeffersonian its prestige, its funding, and its connection to the FBI.
And then there is the fact that Zack, although socially awkward, does have a social network of people he is close to and whom he would share his troubles with. Dr. Brennan for one; Booth, for another. His best friend Hodgins, and his friend and sometimes-confidante Angela. All of these people are people Zack has gone to with moral and personal queries in the past; and Zack had said in a previous episode that if he had a moral dilemma to work out, he would go to both Angela and Brennan for advice first and foremost. He also highly values his family, claiming that the true meaning of Christmas -in one episode- is 40 people clamoring to see you. He also isn't so socially awkward to not acknowledge that although he is a rational empiricist, to his mother he is still strictly Lutheran.
All of that put together means that unless there was a very good explanation, the character known as Zack Addy for 2 seasons and one truncated season would not have joined up with a serial killer. We in the viewing audience and Zack were not given that very good explanation. Instead, we were given a logical argument a first year philosophy student could have dismembered in less than 2 minutes, and one that Dr. Brennan dismantled in less than a minute. Remember Zack Addy. He will be missed.