The Federation is in a bid for what appears to be a stable wormhole, with The Enterprise as its representative. If the wormhole is actually stable, it could mean a cheap form of transportation to wherever the other end of the wormhole happens to hang out. The Ferengi suddenly appear and demand to be included, after which things start to get messy. The Enterprise obtains permission to run some tests on the wormhole, with the stipulation that they share all of the data collected with the other bidders. But, since the Ferengi don't trust any one, the Ferengi insist on being allowed to run their own tests. Meanwhile, Troi has a passionate affair with one of the negotiators who is secretly a mind-reader as well. Their relationship becomes strained when Troi finds out that her new lover uses his powers to deceive his competitors and otherwise gain the advantage. The shuttle team goes through the wormhole and discovers that it is not stable and that the other end does not stay in the same location. They try to warn the Ferengi, but the Ferengi shuttle won't take their word for it and end up stranded, with no possible rescue. Back at the negotiations, Troi's lover has worked up a ploy with the Ferengi that Troi feels she must call him out on, revealing his secret. She ends their relationship. Everyone learns that the worm hole is worthless, and all go their separate ways.
It's also good to have other things happening in the episode. Distrustful Ferengi are always good for a laugh, even when they get stranded by a worm hole which is almost the same as getting dead. And where there's Ferengi, there's often some sort of gambling, and I find it hilarious that they weren't even invited initially. It was also a nice touch that the gambling centered around a tantalizing scientific possibility. Man, what if there really was a stable worm hole? I imagine that after the newness wore off it would become an everyday super highway, even if they couldn't replicate it, but there's always that Ooooo factor when something like that is first discovered. Kind of like "Oooo, fire." Fiiiiiiiiire. Fire is pretty!
Er, I mean... Yay, science!