Dexter was a TV series that ran for eight seasons between 2006 and 2013. With the character and original concept based off a novel by Jeffry P. Freundlich (under the pen-name Jeff Lindsay), the series garnered praise throughout most of its run with a few notably poorly-received seasons sprinkled in.
The series follows Dexter Morgan, a blood-spatter analyst for the Miami Police Department who is also a serial killer. The entire premise is that he kills only those who deserve death, channelling his urges (which he refers to as the "Dark Passenger") into something that could be construed as useful to society instead of harmful.
While it should be obvious, from here on out there will be heavy spoilers for plot points throughout the entire series as these are in no particular order of significance or chronology. If you have any intention of watching the series and haven't done so yet, please don't read any further.
Whether the series should have ended before it did - or what should have been changed about that final episode - is not what we are going to look at. Instead, we'll try and find the small details that the show put throughout all eight seasons that we probably didn't pick up on first time round.
10. Return To Sender
Initially, Dexter's preferred method of body disposal is to take them out on his boat to an area called the "Underwater Graveyard". This is a deep drop-off in the ocean where he weighs their body parts down with stones in order to prevent them resurfacing.
One of Rita's children, Cody, has a goldfish named Bob who sadly passes away. Dexter assists him in flushing the remains down the toilet, only for the body to resurface shortly after.
In the very same episode, the last victim that Dexter has killed and disposed of is found on land and he is part of the team investigating, essentially being stuck trying to throw colleagues off the trail of a murder that he himself has committed. In reality, the Ice Truck Killer has retrieved the body and deliberately placed it in order to taunt Dexter.
You could also argue that Bob the goldfish appearing back in the toilet bowl is reminiscent of a later time when divers discover the underwater graveyard in its entirety and Dexter is forced to switch to disposing of bodies in the powerful Gulf Stream, relying on the current to drag them far away from detection.