After grilling Quark over the "remains" of a Ferengi who is still very much alive, Odo gets a special visitor. Dr. Mora Pol, the researcher who discovered and educated Odo in his early existence. Odo storms out of the bar, but Mora follows after him with news. He's discovered possible evidence of where Odo came from. A planet six light-years from the wormhole in the Gamma Quadrant.After requesting a runabout from Sisko, Odo and Mora head off with Dax and a researcher named Dr. Weld Ram. Along the way, Mora reminiscences about first discovering Odo was a sentient organism. Much in the same way a parent would tell an embarrassing story about their child. Odo is visibly annoyed.Beaming down to the planet, they poke around the general area. Finding a monolith with unidentifiable writing on it, along with Dr. Weld finding an organism possibly related to Odo. When the monolith is beamed aboard the runabout, the area is rocked by a massive quake.Running to get clear of the collapsing rubble, the foursome are hit by an erupting column of volcanic gas. Odo seems unaffected (due to not possessing a respiratory system), and the crew are beamed back to the runabout.With the others confined to sickbay, Odo pops in on O'Brien examining the organism Dr. Weld retrieved. O'Brien cant figure out what the frigging thing is, due to it constantly changing. Just to be safe, the creature is locked in a level 5 containment field... which seems to do exactly nothing, as the lab is found trashed the next morning, with the organism appearing to have escaped containment.O'Brien heads into the vents to see if the thing escaped up there. After hearing a noise, he finds the thing alright. But it's dead. That appears to be the end of it. Until Bashir is attacked in his lab that night by a mysterious, tentacled blob creature. He drives it off with a laser scalpel and calls security.And that's where things get odd. After an analysis, Dax confirms the dead life-form and whatever attacked Bashir can't be the same thing. When Dr. Mora see's this, he comes to a conclusion. The thing that attacked Bashir is Odo.Mora confronts Odo with this, but he denies it. The two enter into a heated discussion, which eventually comes to a head when Mora demands Odo return to the research center with him. Odo begins to lose his structure, and eventually turns into the beast that attacked Bashir when his emotions overcome him.Turns out the gas that incapacitated the other three had an effect on Odo after all. Mora beats a hasty retreat from security and quickly formulates a plan with Sisko. Volunteering himself as bait to draw the confused Odo creature out and trap him in a force-field.He takes the bait all right. As a massive, misshapen, howling blob creature of pure rage. After futilely slamming into the field a few times, Odo manages to compose himself and return to his standard form.In the infirmary later, Odo and Mora patch things up. Mora suggesting he keep in touch from time to time.
- Amazingly Embarrassing Parents: Though he constantly states Mora isn't his father, he still seems to occupy the role of an embarrassing parent on the runabout trip.
- Artistic License - Anthropology: While it's Truth in Television for some eras, it's somewhat jarring for scientists from an organization as progressive as Starfleet to just grab the monolith when for all they know there might be a sentient species on the planet for whom it has cultural significance.
- Body Horror: The gas makes Odo turn into a large, rapidly shifting blob monster, incapable of anything more than bizarre snarling noises. During the initial stages, it looks like he's melting.
- Everybody Lives: Despite Odo turning into a rampaging monstrosity, nobody gets killed because of it. In fact the only casualty of the episode is the lifeform found on the planet, and whether that counts as a being is kind of nebulous.
- Genre Shift: Deep Space 9 does horror.
- Jerkass: Doctor Mora spends much his time talking down to Odo, interrupting him and then condescendingly talking about his formative years. He's even surprised and outraged that Odo, somehow, doesn't want to go back to the science lab he spent his "youth" in. Mercifully, he does get over it.
- The Killer in Me: Odo is horrified to learn that he's the monster that everyone's looking for.
- My God, What Have I Done?: Doctor Mora nearly says this word for word on seeing Odo's twisted form imprisoned by the forcefield.
- Nightmare Fetishist: At the beginning of the episode, Odo tells Quark he's got an interest in death rituals.Odo: Everyone has a hobby.
- Not So Different: Mora comments that the scientific method isn't too different from police investigations. Odo agrees.
- One-Winged Angel: Odo's bestial form is most assuredly this.
- Riddle for the Ages: What was up with the monolith, and what was its connection to the changelings, if any? We never learn.
- Series Continuity Error: Sisko's comments to Odo about his own father implies that he had since died, even though later episodes would show Joseph Sisko alive and still running a restaurant in New Orleans.
- So Proud of You: Mora is proud of Odo's police abilities.