>>45555
Quite a lot of background story those give. In this episode there were references to those. I think it can be watched without them. Maybe you could read the plot of the original show on Wikipedia or somewhere, if you don't wanna bother with previous seasons.
But essentially:
The hero of the show, Dexter, is a serial killer, mom was killed in front of him (and his brother) when he was a kid. A cop adopted him and raised him. Recognized the psycho and tried to channel it, he gave him a code. He grew up became part of the police force as forensic analyst, murdered killers and dumped them in the ocean. He got gf and a kid. Then things started to fall apart around him, everyone died (like his step-sister, who maybe turned out she was his sister or some drama shit whatever), he fled from Florida to Alaska.
That's it, now you can watch this season.