Lila discovered that Dexter is the Bayharbour Butcher, and captured Doaks in that little hut near the swamp. She wants to help Dexter, /because She still believes that Dexter is her soul mate.../ and blow up the hut, with Doaks.
The Miami police has every evidence that he was the Butcher, so they close the case. Dexter is in safe. The only thing left is Lila, who knows about him. He tries to kill her, but she escapes thanks to Deb, and kidnap Astor and Cody. She couldn't kill them because Dexter saves them. After that Lila run to Paris. Everything comes back to normal. Dexter got back his identity, /The Dark Passanger/, his family, and his peacefull life. Everyone feels bad about Doaks, but that was the only way, so Dexter could survive this. Of course after this, Dex hunt down Lila in Paris. :)
Wasn't bad, but I think the next season gonna be more darker, because the real Dexter is back!
They gonna need a new, badass serial killer against Dexter Morgan! :)