[It's not exactly unusual to find one of the holodecks occupied. While they may have been par for the course for some of the station's occupants, they were certainly a novelty for others. Whatever the reason, there was usually someone looking for something that they couldn't get anywhere else on the station.
What is unusual is the occupant- though who precisely it is isn't apparent at first.
The first thing that is apparent upon entering the holodeck is an intense desert heat. Someone, it seems, has painstakingly programmed the simulation down to every tiny detail. The detailed stonework arches guarding the entrance to a cave in an unforgiving mountainside makes it quite obvious just exactly what this is.
Vulcan. Without the terror that not everyone here remembered.
The heat isn't much lessened
inside, either, though that doesn't seem to faze the individual, sitting with his back against a stone wall far from the center of the space with one knee pulled into his chest, head bowed. The blue of his uniform is plainly visible in the muted light, though he seems quite lost in his own thoughts.
Which, admittedly, isn't all that strange. Only the location really is.]