This is an agreeably interesting and complex story, with a few twists and a surprising ending that Makes An Important Point. Plotting-wise, it's almost (but not quite) worthy of Roy Huggins. (Huggins was never one to Make Important Points.) You can discover these for yourself. This review will focus on the acting.
The various Star Trek series have never been strong on casting. Any of them is lucky to have one really fine actor in the regular cast. (DS9 has two, but out of respect for the other actors, I won't name them.) I'm inclined to say that TNG doesn't have //any//. In "Gambit", we see two of them at their worst.
Frakes and Sirtis are arguing over who's more upset at Pickard's apparent death. They raise their voices as if they're trying to be heard at the back of a stadium with a non-functioning PA system. They wildly over-emote in an manner more like a high school production of a Shakespeare tragedy.
It's some of the worst "acting" I've ever seen in an American TV series. (The absolute worst is Martin Landau's death scene in the "Bonanza" episode "The Gift".) Peter Lauritson, the director, must have been in a rush, or didn't care that Frakes and Sirtis broke one of the most-basic of acting rules -- restrain yourself. You have no where to go from "all out". Frakes and Sirtis are cringe-worthy without the saving grace of risibility.