*** (3 stars out of 5)
Nagilum only less visually ambitious.
Hoshi and Trip catch a silicon-based virus while snooping around a Klingon latrine (!) Whatever archeological treasure they hoped to dig up... could it EVER be worth it? Disease symptoms include discussions of previously unsuspected back story. Hoshi has an aikido black belt?? And plays poker??? And was expelled for breaking her commanding officer's arm??? Hoshi??? Meek, withdrawn Hoshi. Fine, I'll accept it, but I think you meant B'Elanna Torres. Also, Hoshi's pattern-sensing genius extends to picking computer-code quarantine locks and going for a feverish wander. "Yeah, she's full of surprises today," says Trip. Surprisingly bad quarantine, too. Even a chair wedged under a door handle would've worked better!
Humans are surprising to the observers, too. The more jaded of the pair of godlike scientists had never in 800 years seen a captain infect himself trying to help. What you get for watching jerks like Cardassians and Klingons, I guess. Or is it just that everyone else sends doctors to heal people?
"Experience compassion for yourself," Archer challenges the observers.
The aliens agree to save lives instead of being jerks, and also start sprucing up for an official first contact with humanity. "That will barely give us 5,000 years to prepare."
"Observer Effect" is a good bottle show, but I'm baffled when The Original Series had better special effects to depict these nostalgic special guest aliens than the modern.