I won't go into a detailed plot synopsis, suffice to say that Voyager is sent to investigate a lost Earth probe, eventually finding it in the hands of survivors of a doomed civilization that used technology from the probe to eventually destroy itself.
By far the most interesting aspect of this episode is the fact that it is the first Federation mission assigned to Voyager after being lost in the Delta quadrant. As for the rest of it, the motivations of the alien race (yes, yet another hominid species with some facial appliances stuck to their faces) are nonsensical. So, you found this probe and mishandled the tech and you're blaming people 300 years later? Dumb. These aliens would make great Catholics, with their original sin.
Boil it down to the actions of the alien leader and he seems even more stupid. Voyager ambles along, demonstrates that, even though they acknowledge that Earth could be seen as partially culpable for their plight, they want to do their best to correct the terrible ramifications... and he does his level best to thwart Voyager's every move to help them. If you had the right actors, who could maybe sell the idea that the aliens have been driven insane by their plight, this idea might work. But the people they hired aren't those actors, so all you think while you watch this episode is "Why the Hell is he doing that?!?!". Why? Because script, that's why.
Outside of the idea of finally being able to carry out Federation-issued plot lines, skip this lame attempt at a morality tale