At the Castithan equivalent of a bachelor party, Alak is pressured to sleep with a hooker (In Casti culture, it's a legit practice. In Earth culture, it's something you do when drunk then feel bad about). He doesn't want to cheat on Christie and fights with his friends, a brawl that leads to a big hole in the wall of the NeedWant. There's a dead body in the wall!
The body is seven years old and ID'd as being that of Hunter Bell, who, true to a good "whodunnit" had history with every single person in town (thus translating to "everybody had reason to want him dead."). Let's review.
First, Hunter was Kenya's ex-husband. In flashback we see Kenya started out as a waitress at the NeedWant and also hadn't mastered how to work good hair. Hunter also used to beat her. Suspect #1: Kenya
Amanda, seen in flashback as Mayor Nicky's assistant, is not happy that her sister is getting beaten by Hunter. Suspect #2: Amanda.
More flashbacks! Turns out back in the day, Hunter Bell ruled the criminal element of Defiance and Datak was a hired thug. When Datak demanded more of a stake due to the business he's helped raised, Hunter humiliated him (which we know from last episode, when Datak is humiliated, it usually results in someone dying). Suspect #3: Datak.
Amidst all this, Irisa discovers the dead body of Jerret, the NeedWant bartender who worked for Hunter back when he owned it. He seems to have died via a blade - and a Casti charge blade fits the bill as a potential weapon.
Given the blade connection (Datak loves his knives) and his past animosity with Hunter Bell, Datak is arrested. Datak denies killing Hunter and Nolan releases him. As he tells Tommy, Datak's ego is too big to ever keep Hunter's death a secret - he would have displayed his body in the town square.
Nolan gets the Scooby Doo award for figuring out that the guilty party is.....Mayor Nicky! There was residue found on the dead Liberata that's consistent with excessive amounts of oxygen, which is fatal to a Liberata. Nicky, of course, always has oxygen handy.
But Nolan doesn't arrest her because...Nicky's dead! She left a note confessing to Hunter's death, and then committed suicide. Except, she didn't (well, commit suicide that is, she is guilty of murder).
Here's what really happened: We found out that Nicky is actually an Indogene, similar to the astronaut McClintock in Episode 8. Hunter Bell walked in on Doc Yewll (who knew this) examining Nicky and realized the truth. To keep him quiet, Nicky killed him. Yewll and the Liberata bartender (who Nicky paid off) saw everything.
That's not all! Nicky actually didn't kill herself. YEWLL killed her! Killing the Liberata bartender was the last straw for Yewll, after watching Nicky devolve into a genocidal monster (read: Sending the Volge to attack Defiance). So she offed her and made it look like a suicide.
Except for now Yewll is in possession of the Kaziri, the very thing that made Nicky all about mass murder. Question is: What's she going to do with it?
While all this is going on, there's a wedding to prepare for! Christie was expecting to get something borrowed, but instead she gets a Telo, the Castithan wedding mask that covers your eyes and looks like something She-Ra would wear if she were into S&M. She wants to, you know, be able to see her groom on her wedding day but also wants to respect Alak's culture.
Trouble's brewing because Rafe takes Datak aside and lets him know that he's willied the mines to the Irathients, so there is no way in hell the Tarr family will ever get a piece of them after Rafe goes.
An infuriated Datak orders Alak to end the engagement to Christie (after all, there's no benefit for Datak anymore). Alak, who does this whole scene in a loincloth, refuses.
But filial loyalty gets the best of him and he breaks up with Christie. She's devastated. Rafe, who has figured out why Alak did this, tells his potential son-in-law to follow his heart.
Which, bam! Means there's a wedding. Christie ditches the Telo and she and Alak say "I do."