This Riker episode is the TNG equivalent of "The Enterprise Incident" from the original series: an outside the box story exploring a genre the series had previously avoided. And despite a teaser idea nobody is going to believe, ("Picard was killed off-screen in-between episodes in the middle of the season") the story works because the Enterprise crew has no reason to doubt this, and we can't help but be swept away by their emotions. (It's also just plain fascinating to see TNG without Patrick Stewart even if it's only for a brief time.) While the crew is grieving, we as an audience are left with the mystery of what really happened; and it's fun to see the puzzle pieces come together as the episode backs into a space pirate story, reminiscent of "Buck Rogers" and "Raiders of the Lost Ark."
And darned if "Galen" doesn't have the time of his life playing the bad boy!