This show is like a who-done-it in reverse. You will come to understand that the evil genius will take revenge on one or all of her former/current lovers who she brings together at a table in a bar. The crime hasn't been committed yet, you know who will do it, but you don't know when, how, or to whom. All the ex's of one woman are brought together (three men and yes, another woman) to bring this plot together in dark comedic fashion.
The first thing you need to understand about this movie is that it is dialogue driven. Almost everything takes place at a table with flashback scenes to fill in the gaps. There is not much by the way of action. However, the scenario is good enough to drive the movie and the twists are interesting. If you can't take that much reliance on dialogue to make it work for you, chances are you won't like the movie. I admit, I normally don't like this kind of movie. This one worked just well enough for me.
I can't say much more about plot without spoilers so I won't. The actors are all very recognizable and enjoyable, though not in the renaissance of their careers. I was glad to see each one. Katee Sackoff works well as the evil genius specifically because she is a bit quirky. She sells it well. I always like Seth Green. Michelle Trachtenberg is definitely on my list to see in movies as the sexy ex girlfriend of another woman. Harold Perrineau and William Baldwin round out the primary players.
I want to give a specific mention for Lauren Fray (from GREEK) though she had a very small part as the waitress. She says very little but has such an interesting manner about her that you wonder if she will play a bigger part somewhere in the story. I hope to see her in bigger movies in the future. She does off-the-wall comedy very well. Each of these actors are perfect for this type of movie and they make a success of something that could have gone very poorly. Rent if it sounds good to you. I don't think I would watch it over and over.