Annoying children take over the Enterprise by shaking their fists. Yes, that pretty much sums up the whole episode; there is not much more to the plot than that. Kirk becomes a social worker and tries to help the children work through the grief of loosing their parents, but accomplishes nothing. There's a problem with putting children into adventure shows: they slow down the plot and they are typically very bad actors. I put this episode up there with Spock's brain and Hippies in Space as the worst Star Trek episodes. All three have one common element: annoying adolescent antagonists. If producers wants to put children or child-like characters in an episode, they should make the kids cute or smart or grappling with issues. Kids as evil villains just doesn't work.