Odo gets mixed up with a female with connections to a criminal syndicate.
I think this is a mediocre episode with some good moments.
The plot is quite noir-like in that Odo gets involved with a femme fatale (ish) and there is a little a bit of a mystery around her background. However, for me the plot does not unfold in an intriguing way and the antagonists are not threateningly portrayed. The focus is more on the character development of Odo through the romance and whilst the mystery is explained in exposition dumps.
As with most Star Trek romances I think it does not work very well due to the episodic nature of the show and small amount of chemistry between characters. Arissa for me is not special enough to warrant a major character like Odo falling in love with her and, as usual, it feels these characters are in love because the writers say they are. Dey Young is not bad, but plays a standard, damsel, love interest character with no major acting challenges.
The positives I take from the episode are how it shows Odo in a physical relationship and it incorporates his changeling biology into certain aspects of the intimacy. This lays the foundation for future storylines.
Easily the most entertaining scenes involve the other DS9 regulars in their supporting roles for the story. All the gossipy scenes are humorous and Bashir's holodeck program is very funny. Colm Meaney's appearance is hilarious.