The Alternate (***)
I'd like to be generous to this episode and say that it served as a subtle hint of what is to come, just like all the Dominion references that are being thrown about recently, but it doesn't really. In fact, one of the problems with this episode is that it tantalisingly suggests early on that it may reveal information about Odo's background, but it abandons that element halfway through the episode so that it can do a monster story. I know that the writers had nothing planned for Odo's people at this point in the show, and they had originally planned not to show them at all, but it still feels like a bait-and-switch to seem to offer new information about Changelings and tell a different story instead. And what about that lifeform they found that was similar to Odo? Once it dies they just forget about it. Why can't they go back to that planet and look for another one? Vortex
did a better job hinting at Odo's people and the guy in that episode was pretty much lying.
What the episode does provide is an insight into Odo's past and how he came to interact with humanoids, and the resentment he harbours for Dr Mora Pol. Firstly, I don't get why everyone thinks that Odo views Mora as a father figure, unless they're basing that on their shared hairstyle, which seems like an odd thing to decide parenthood on. ("I'm sorry Captain Sisko, but ever since you shaved your head it has become clear that you're not Jake's real father. We're taking him away now.") Anyway, some toxic gas causes Odo to develop multiple personality disorder, which makes about as much sense as everything else about Odo's "biology". Odo's Hyde personality is acting out against the Jekyll personality's resentment of Dr Mora and tries to kill him, which leads to a scene where Odo melts and is eventually caught in a forcefield so that the gas can be removed, or something like that. Honestly, I was pretty tired while watching the episode and the second half began to lose my attention.
In summary, I liked the Odo/Mora stuff, I wasn't so fond of the monster stuff, and the episode gets a bonus point for having Admiral Jarok in it.
Form of... something: 11