Holy wow, I did not see that ending of this season coming, it was one that I really didn't expect and is a ballsy move that will definitely change the show.
First off though a quick round up of the first 45 minutes of the episode. So as expected Dexter finally got to the Trinity killer and did what he has been wanting to all season, kill him and then let the ocean take care of the rest. However as this season has shown us the path to this was filled with many obstacles and this time it was a little time in jail that got in his way from doing the deed when he wanted to. The consequences of this were much graver than Dexter expected them to be but more on that in a bit. Trinity is then identified by the four walls symbol on his van that Scott (the boy he kidnapped- the homicide team link missing 10 year old boys before a bath tub kill and therefore to Trinity) draws and the police storm Arthur Mitchell's house with Dexter (as Kyle ) inside. Through some quick thinking he hides in the coffin in the garage, though due to his lack of police flak jacket Debs is confused as to why he was in the house so quick and without the correct protection on. Lucky for Dexter though her mind is far too occupied with the information that she has on Dexter's biological mother, this has led her in identifying the 'Ice Truck' killer as his brother, though he pulls off a convincing performance to suggest he didn't know any of this already.
Now to the real crux of the episode, the conversation between Trinity and Dexter before he kills him revolves around fate and free will, Arthur stating that it is all God's will and that it is all over now any way. Dexter does not agree with Arthur and this fate positioning and we see him muse that he will get rid of his dark passenger for the sake of his family he really does love, he looks at the moon as he is disposing of the body and thinks of Rita. When he arrives home to pick up his holiday stuff he has a voice mail from Rita saying that she has heard that the moon will be beautiful tonight and that she has to pop home to pick up her ID as she forgot it, it is at this point that I realised something bad might have happened. Dexter rings her phone which he hears inside the house, and then hears Harrison crying. The discovery is one that mirrors his early life, Harrison is sitting in a pool of his mothers blood who is lying dead in the bath tub and it is at this point that Dexter thinks that Arthur was right about fate, it is also at this point that I have my hand over my mouth in shock as I can't believe they are ending the season this way.
I for one am sad to see Rita go, though as a story function this is an exciting one and will lead to many possibilities like how will Dexter cope as a single Dad? The dark passenger will I imagine be coming out of early retirement in full force and will this bring Dexter's secret to the surface. How will he explain the Trinity killer picking him and his family as a target?
Over at Entertainment Weekly they have an interview with executive producer Clive Phillips who clears up any confusion regarding this season ender.