There is a similar question here that was closed for some reason as being opinion based. My question is not a general question about whether or not the Founders are able to establish a telepathic link with solids, but a specific one about this episode and the mechanism for how Odo was able to establish a link with the other crewman, if that's how it happened.
DS9 "Things Past":
BASHIR: As far as I can tell, the four of you were locked into some version of the Great Link.
ODO: The Link? How is that possible? I'm a solid now.
BASHIR: Well, it seems you're not as solid as you think. When I ran a neurochemical scan of your brain, I found residual traces of morphogenic enzymes which I've only detected before in changelings.
ODO: When the plasma storm hit the runabout it activated the enzymes and initiated a telepathic response.
BASHIR: Your mind reached out to find other changelings to form the Link, but all it could find was Sisko, Dax and Garak.
ODO: And just before the accident, I was thinking about the executions. Somehow being in the Link must have forced me to relive it, and admit the truth about what I'd done.
I was really confused by this episode.
My understanding is that although Odo did have a certain calling for the lake early on that is not indicative of outright telepathy. It certainly could have been a past memory or something planted there by the founders. In any event physically being in the lake created the link between the changelings.
Although Bashir infers somehow that there was a link between the four of them there is no precedence for this or mechanism explained other than Bashir simply stating that Odo's mind (as you'll see below, even though Odo is now a solid, changelings don't have brains, so it couldn't be his mind reaching out telepathically, right?) "reached out."
An additional fact to consider is that we have no example of a changeling creating a link with a solid. There is no in-canon mechanism or example of this that I know of. If this ability existed then the dominion would have used this as a weapon or strategy over and over again during the Dominion wars.
Solids are not morphogenic and changelings appear to be immune from telepathy thereby precluding the possibility for a telepath to initiate a link.
DS9: "Dramatis Personae":
BASHIR: Possibly. What are you getting at?
ODO: Doctor, I believe the Klingon brought the matrix with him and everyone in Ops was affected except me. Without a humanoid brain, my system rejected it.
Was Odo connected to the great link in this episode or was Odo just connected to the other three solids with him? If he was connected to the great link, how could a link be established from so far away without being in physical contact with the lake? If he was just connected to the other three solids how was he able to establish a link subconsciously with solids (and without being in physical contact with them)? Or is there some other explanation for how this connection occurred?
If you want to include in your answer an explanation of how the various characters were controlled, the narrative occurred, etc. that'd be helpful as well.
Any star trek manuals, reference materials, or writers notes are welcome.
(Richard you gave me a link before that had some good writers notes in it. I was wondering where that reference material came from maybe there's an answer there.)