Rosalee receives a letter from her mother. It's the first correspondence the two have shared in over seven years, and Rosalee is nervous about why her mother wants to meet with her. Monroe agrees to accompany Rosalee to the dinner.
Across town, a war veteran, Ron Heard, encounters an old stranger with a grudge against him. As much as the woman tries to confront him, the man refuses to speak to her. She assures him, however, that she's not going away until he confesses to his crimes against her. Moments later, Ron is brutally attacked in his home by a vicious lion-like Wesen with a scorpion tail.
Nick and Hank arrive at the scene the following morning. A cursory investigation reveals that Ron is a former soldier, and that his war medals have been stolen. The hole in Ron's chest is too big to be a bullet hole, so what killed him? The detectives interview a few of Ron's associates to find out more about their victim. They learn he was a distinguished soldier who made a few calls to a co-worker right before he was killed.
The detectives head to the home of Jim McCabe, Ron's close friend and co-worker. However, Ron's accuser made it there first and threatened McCabe. It seems she has a grudge against Ron's entire battalion.
Nick and Hank arrive at the local DFW to learn more about their veteran victim. The hostess at the DFW knew Ron well, and she's crushed to hear about the tragedy. She tells the detectives about a young woman who was involved in a dispute with Ron just before he left. The detectives get a rough description of the suspect, along with a bloody bar napkin that the woman left at the table.
Monroe and Rosalee arrive for the stressful dinner engagement, and Monroe gives Rosalee a last-second pep talk before they head inside. Rosalee's mother is very happy to see her, but her sister, Dieta, doesn't share the same enthusiasm.
Nick and Hank head to Ron's office to question his boss for any possible leads. Nick asks why Ron called his boss immediately before his murder, but Ron's boss is reluctant to divulge any information about the mysterious woman from the DFW. While investigating Ron's military friends, Hank discovers that another member of Ron's battalion was recently murdered. It looks like somebody is working his or her way through a hit list.
During Rosalee's awkward family dinner, Dieta chastises her younger sister for not returning home after their father died and, more importantly, for not attending his funeral. Rosalee reveals that she didn't attend the memorial service because she was in jail at the time, and she's been avoiding them for the past seven years because she feels terrible about it. Rosalee's mother eventually makes amends with her estranged daughter, but not before Dieta threatens Monroe's life.
At his home, Ron's old military buddy, McCabe, presents his wife with a detailed confession of his battalion's actions four years prior. Disgusted by the admission, his wife advises him to burn the confession immediately. Unfortunately, it's too late for that. McCabe heads to the living room to find his wife stabbed in the chest. Before he can dial 911, he suffers the same fate and dies at the end of a giant scorpion tail.
During an interview with another veteran, Nick and Hank learn that Ron's platoon committed some serious crimes while working as military contractors, including the rape of a young woman named Frankie Gonzalez. Nick and Hank are able to tie Frankie to the murders. Now they just have to find her. A tox report from Wu confirms that the victims died from scorpion venom, and Juliette finds records of a Manticore, a lion-like Wesen with a scorpion tail, in Aunt Marie's trailer.
Nick and Hank track down Frankie Gonzalez, but she insists that she didn't murder any of her attackers. She proves it by morphing into her Wesen form, but she's not a Manticore. Frankie says the only person who knows she's in Portland is her former commanding officer, one of Nick and Hank's sources. He must be the Manticore.
Frankie's C.O. faces off with one of the soldiers, who is also a Manticore. The Manticore battle completely destroys the DFW, but Nick and Hank interrupt just in time. Unfortunately, the vigilante officer suffers a fatal knife wound just before the detectives arrive. They can't arrest the soldier for his crimes against Frankie, but now they have him for murdering the commanding officer. Frankie is off the hook and justice is served, Grimm-style.