Voyager crew members appear strangely to be on a mission at Starfleet HQ.
The story starts off with mystery before it inevitably reveals a premise that is somewhat silly, but enjoyable if you can suspend the disbelief.
For me the strongest moments are the character exchanges between the likes of Chakotay, Janeway and the guest characters. All the respective actors do a good job with the material they have, particularly Ray Walston.
The themes of mistrust and Cold War type relations feel close to the original series, The Undiscovered Country and TNG, whilst the setting and aspects of the plot resemble the DS9 episode Homefront.
I think your appreciation of the episode will be impacted by its portrayal of a previously seen antagonist. For me it does not quite gel with what we saw in other episodes, but it gives a consequence to actions previously taken by Janeway and fits with the positive Trek ideals.
For me it's a 6.5/10, but I round upwards.