| Episode cast overview, first billed only: | |||
| Michael C. Hall | ... | Dexter Morgan | |
| Julie Benz | ... | Rita Morgan | |
| Jennifer Carpenter | ... | Debra Morgan | |
| Desmond Harrington | ... | Det. Joseph 'Joey' Quinn | |
| C.S. Lee | ... | Vince Masuka | |
| Luna Lauren Velez | ... | Lt. Maria LaGuerta (as Lauren Velez) | |
| David Zayas | ... | Sgt. Angel Batista | |
| James Remar | ... | Harry Morgan | |
| John Lithgow | ... | Arthur Mitchell | |
| Geoff Pierson | ... | Deputy Chief Tom Matthews | |
| Julia Campbell | ... | Sally Mitchell | |
| Mary Mara | ... | Valerie Hodges | |
| Brando Eaton | ... | Jonah Mitchell | |
| Vanessa Marano | ... | Rebecca Mitchell | |
| Jake Short | ... | Scott Smith | |
As the noose tightens, Arthur warns Dexter to back off. But Dexter will do anything to stop Arthur from eluding him, even if that means putting himself on the wrong side of the law. Rita acknowledges the rocky relationship she and Dexter share, but reaffirms her support. Meanwhile, Batista and LaGuerta face the consequences of their actions and now that they are married agree to move in together. Debra finally learns that Dexter is the Ice-Truck Killer's brother and tells Dexter. She then tells him he is the only constant truly good thing in her life and that she loves him. At the culmination of the episode, Dexter finally captures and kills Arthur, but then goes home to find Rita dead - apparently killed by Arthur hours earlier in the same manner as the other Trinity bathtub victims. Dexter finds Harrison, alive, sitting in a pool of Rita's blood.
For the past 3 season finales, Dexter has ended up in a happy place. He's killed the main threat of the season, then goes home and kisses his wife Rita and spends happy time with the Family. As a viewer, you can be perfectly satisfied watching this same loop over and over at the end of each season. That's why making the choice to kill Rita is simultaneously heartbreaking and amazing. This shows true intelligence from the writers. They are willing to push the envelope even when they have a winning formula. Can't wait to watch season 5, and RIP Rita. Julie Benz was great and will be missed!