William Sadler, last seen a few episodes before in "Inter Arma Enim Silent Leges", returns to reprise Sloan, with Bashir and O'Brien taking a journey inside the mysterious agent's head (which conveniently takes on the appearance of the station, giving the series a cost saving bottle show). The concept has an early season feel to it and is particularly reminiscent of third season's "Distant Voices" but feels out of place in "The Final Chapter", the serialized nine episode finale for the show.
The premise itself, built on the idea that Section 31 is behind Odo's disease and knows of a cure, is based on assumptions from Dr. Bashir. Yet unlike real life, instead of making an ass out of himself and mption, he turns out to be right. Unfortunately, the "Inside Sloan's Head" gimmick never develops enough substance to make it a serious drama, with too much time spent on Brannon Braga like mind games and not enough time developing a story. What the script really needs is more money, allowing Bashir and O'Brien (and or Odo) to visit the headquarters of Section 31 and seek out information about the disease that could lead Bashir to develop a cure. (In fact, this was the original plan until the producers needed to find a way to save money for the final episode of the series). Instead, the cure becomes a MacGuffin with a simplified "behind door number three" climax. It's a disappointing waste of Sloan who deserves better in his final appearance.