A transporter accident creates a Borg drone with advanced technology.
One of the problems with there being 537 stories before the episode you’re writing is that it’s very tricky to come up with a story that hasn’t been told before. This episode is basically I, Borg, with a bit of The Offspring mixed in, with even a hint of Tuvix as well. That would be OK if the writer had had something new to say, but they don’t.
Nothing is particularly done badly, though. The new Drone never comes alive as a character (as Hugh did in I, Borg), but we do see some interesting development from Seven as she convinces him to follow her path. The Doctor is unusually annoying this week, but fortunately this is mainly limited to the opening sequence. And there’s a nice moment between Chakotay and Kim early in the episode.
538 down, 199 to go.