The End of 'The Perfect Pair' Explained: Who Killed Merritt Monaco?

Who killed Merritt? And why?! The series runs through all the obvious – and not so obvious – suspects in the first five episodes, only to drop some absolutely wild bombshells in the final chapter. Let's break down one juicy secret at a time and get to the bottom of this whole thing.

Greer's secret brother and an even more secret past

At the beginning of the last episode, Greer's husband Tag (Liev Schreiber) has just thrown a drunken fit at her latest book launch. They see, they are not the most perfect couple after all. Especially because Tag is constantly cheating on her and has impregnated several women, including Merritt, but he is not a killer. He is sour on Greer because he had tried to frame him for Merritt's murder. When he gives the police the information from his Fitbit-like device, it is revealed that he was dozing in bed at the time of Merritt's death, but the second person in the bed was awake.

The police bring Greer in for questioning and find that she was on the phone with a shady guy named Broderick Graham at 3:08 a.m., around the time of Merritt's death. They also found a telegram from Scooter Dival (Ishaan Khattar) to Broderick for $300,000. They assume Greer used Scooter to pay a hitman to kill her husband's mistress, but what they don't know is that Broderick is her brother. Oh God!

Thus begins the wildest and most surprising series of explosive revelations of the entire series. Greer has been supporting her no-good brother for years. Okay, that's not that offensive, but the existence of a secret brother seems to come out of nowhere. The soap opera vibe is strong, and I say that with the highest compliment of all. And then! When Greer gets home, she lets loose on a breathless, goggle-eyed tirade about the truth about her and Tag's relationship. They were never the “perfect couple.” Broderick was also Greer's john when she was young, and she was a high-paid escort. Tag was a client so infatuated with her that he eventually snatched her for life. And in an ironic twist of fate, Greer ended up paying for everything with her hard work all this time.

The pentobarbital diversionary tactic

Now why should Greer have to pay for everything when the Winbury family is literally made of money? Well, there's a trust, you see, and the trust isn't released until all of the Winbury children – presumably all of Tag's descendants – are eighteen years old. It feels weird that Tag won't get his money until his children are of age, but I guess trusts can be set up in all sorts of crazy ways? I don't know. Most of us will never really need to know how trusts work, so we'll just play along.

The Winbury children are shocked by this revelation about their mother, but there is still a killer on the loose. Ameila's mother uses this moment to make her own revelation, namely that she had three tablets of pentobarbital in her medicine bag for emergency self-euthanasia should the pain associated with her cancer become unbearable on the journey. This is obviously a very sad twist in the narrative, but The perfect couple doesn't dwell on the tragedy of it all. Instead, the show centers on the dumbest of the Winbury sons, Thomas (Jack Reynor), and we get to see what shenanigans he got up to on the day of the rehearsal dinner. Thomas often stole pills from other people in a game at the private school he called “prescription roulette.” So when he stole a pill from Amelia's mother, he thought it was an Oxy, not a potential harbinger of death.