Headscratchers / Star Trek: The Next Generation S3E9 "The Vengeance Factor"

• What the hell was stopping Riker from tackling Yuta after hitting her with a stun shot from the phaser? Once easily restrained she could have been beamed back to the Enterprise's brig and held by security, pending a decision on what was to be done with her. Instead he outright murders her, despite having many other options available to do otherwise. And despite it being clear she felt hesitation and remorse over what she was doing, still had humanity left. Picard also qualifies to a lesser extent. All through the protracted exchange he could have intervened in some way as well, as he has in many episodes, but instead merely remained seated and silently watching it all play out.
  • If he tackled her, there was a risk that she could force him off, or could accidentally touch one of the Gatherers. Picard not acting? Sheer idiot ball.
    • It actually wouldn't have mattered if she had touched any of the Gatherers other than Chorgan, since her virus only affects members of the Clan Lornak. The simplest thing would have been to beam either Chorgan or Yuta to the Enterprise and then go explain. Or at least, rather than telling Chorgan to stay seated for some reason, Riker should instruct him to make a run for it.
  • Riker doesn't know exactly how does the virus work. For all he knows she can kill from afar so attempt at constraint or beaming Yuta might fail. She admits being enhanced and brushes off stun so there's a good chance she is stronger than she looks.
• Everyone reacts with instant surprise upon discovering that Yuta hasn't visibly aged in 50 years. They also serve on a ship with Guinan, who is centuries old and looks exactly like a human in her 30s. Was everyone already familiar with an obscure species' lifespan?
  • Presumably Acamarians age at a similar rate as humans and the crew knows this.
  • There are only three people present in that scene; being Data, Riker and Crusher (and in Data’s case, we don’t actually see him be surprised). All three characters had every reason to have a knowledge of the Acamarians’ life span. Given Data's tendency to memorise pretty much every fact about every obscure planet, it's rather implausible that he wouldn't know something as basic as the life expectancy of the Acamarians when they were on a mission involving their planet specifically. As for Crusher, she is a doctor and would be expected to have at least that level of rudimentary knowledge especially considering she had Acamarians on the ship and given she’d studied the cause of death for one Acamarian. It’s unlikely she wouldn’t have looked up basic details of their biology such as rate of cellular decay and life expectancy. As for Riker, there was a joke early in the episode where one of the gatherers mocked Marouk when she suggested they hadn't changed in a hundred years and they suggested that, "You should know. You were there." The joke, which was conducted in full view of several crewmembers of the Enterprise including Riker himself, only made sense if an Acamarian being old enough to have been around a hundred years ago would be considered comically old. This clearly implied that the Acamarians were not a long-lived species. So even if Riker hadn’t looked up the life expectancy of the Acamarians, he certainly would have expected them to age over a 50 year timespan. So all three people present at the scene where Yuta's age was revealed, would reasonably be expected to be shocked that she hadn't aged.
• In "The Vengeance Factor", Riker finds out his sex bunny of the week, Yuta, is going around killing descendants of the clan that wiped out hers. He goes to stop her with a phaser. Alone. Without, say, Worf or Data. He tries to get her to call the vendetta off. She refuses, and keeps going after her target until Riker shoots her with a blast that vaporizes her. There was no middle ground here? Like wrestle her to the ground to keep her away from the target? Does she have super strength? Literally her only weapon was a virus engineered to kill members of the other clan and no one else. Even if touching her would have given Riker the virus (and he already had touched her), he'd just need to avoid touching this guy he'd never see again. No other option is considered. While the lower level phaser blasts don't knock her out, they do slow her down. How about getting the target away from her while keeping her immobile? Riker tells him not to move! And he doesn't! Neither does literally anyone else. Picard is right there — he doesn't try to tackle her or anything. Or...beam her to another location? Beam her victim away? There's at least a dozen ways to resolve this that don't involve killing her. It's almost as if the writers wanted Riker to have to kill her, but didn't want to create a situation in which there was no time to find another way, because then they wouldn't have been able to look tearfully into each other's eyes as Riker begs her to stop.
  • As you say, the writers wanted him to be forced into a position where he has to kill her; it just doesn't play that way on screen. It's really a problem of... execution (ducks tomatoes).
    • Picard not moving is a Special Effects Failure — apparently they were unable to create the disintegration effect with Picard moving (see Trivia).