What if history’s most mysterious serial killer was the man who gave you life?

This scenario comes to life in Gary Stewart’s book, “The Most Dangerous Animal of All.” The television series on FX is a four-part documentary-style investigation of who his birth father really was and why he abandoned him.

The series follows two timelines that seem to diverge around the late 70s to early 80s from Stewart’s father and the zodiac, respectively. Emotion pours through the series, and viewers will want to root for Stewart in his search.

When Stewart reconnects with his birth mother, she fills him in on details about his father and how they met. However, through Stewart’s own investigation, he discovers that his father could have possibly been a murderer.

But he wasn’t just any murderer. Stewart was trying to find out if he was known as the Zodiac Killer, who killed over 30 people.

Everything his mother tells him happens to relate back to him being the zodiac. Coincidence or convenience? Viewers will have to decide that for themselves.

The series leaves viewers at the edge of their seats, waiting for the next piece of the puzzle in the short episodic installments. It also revolves around Stewart’s need to solve whether his father and the zodiac are the same people.

Fans of true crime and documentaries will be truly intrigued to dive deep into the personal narrative of Stewart’s life and the historical presence the zodiac has left behind in American history.

However, hints of skepticism will pull through for a viewer, like water in a straw.

The series shows how Stewart’s obsession with this investigation bleeds through other parts of his life; how his relationships with his family and wives deteriorate before his very eyes.

Old footage of the zodiac case is presented to give context to what’s going on. It gives viewers who aren’t familiar with the case an idea of the stakes Stewart deals with to get his theory right. We also hear from detectives and people who were around during the height of the zodiac case.

Audience members will notice how the timeline of the zodiac murders/case matches with Stewart’s findings, which means his theory could be true, but viewers shouldn’t be fooled by Stewart trying to convince them and possibly himself, of his parentage.

Which begs the question, how much of the book is fact over fiction? Well, the series answers it, somewhat.

Again, Stewart’s theory is compelling but when it comes down to it, the inconsistencies of the evidence presented versus the evidence the police have don’t add up completely.

Theories are shot down as actual evidence/investigation done by experts. It disproves Stewart’s theory about who the zodiac really was.

Stewart has invested a huge portion of his life to figure out how he could be connected to someone like his father. After finding out so much information, he had to rethink his whole life and what he knew.

Viewers will be enraptured in this tale of self-discovery and identity, but it will tug at their heartstrings. They’ll find what makes a person behave or be a certain way that much more intriguing.

The documentary will leave viewers with many questions. Just like any other serial killer, we ask ourselves: “Why did they stop?”