I’m not sure what your goals are for this script (practice, contests, production, etc.) but it has some problems that should be addressed. I’m not crazy about the first minute being a monologue in which we watch Chance sit in a chair and smoke. Not a terribly engaging visual to start things off. We get a quick scene to establish that he’s socially awkward with women, which is good for character development, but in this case not relevant enough to this story to warrant a full page. He then kills three people while espousing philosophical lectures. I haven’t studied philosophy, so most of what he said didn’t mean any thing to me, making it difficult for me (or anyone in the same boat as me) to stay engaged. It would be better if he “dumbed it down” for his stupid victims (and us), and just sprinkled in some of the high-falutin’ philosophical mumbo-jumbo for flavor.
We then get to Karen, finally someone who “fights back,” which I like. Then we’re hit with a set of coincidences that are off the chart. It may be that this was orchestrated to make a point about destiny, pre-destiny, cosmic fate, or whatever, but it only struck me as so beyond incredibly unlikely that I was distracted from trying to find the symbolic meaning in the events. In other words, I was too busy groaning to take it seriously.
There are a few writing adjustments you need to make. There is a consistent misuse (non-use) of apostrophes, especially when indicating possession. Jackie’s Place, Ben’s Apartment, etc. Avoid using passive voice in a screenplay. “Ben is limp. He is dead.” This is passive and weak for a script. Try, “Ben goes limp, dies.” (or something more active so we can “see” what’s happening on screen). Ellipses always consist of three dots (never just two), and should be used sparingly.
There was a definite creepy element working here, and I was interested to see how this was all going to play out, but the ending put me off and wasn’t worth the work to get there. I’d much rather see Karen overpower Chance in a philosophical showdown at the end. I think it can still work that she turns out to be his sister, but they need to come upon this fact themselves without the device of the Family Finder. And for it to work, you need her arguments to include something about randomness, or fate, or the forces of the universe directing events so that this “chance” encounter actually supports her intellectual position. I like the idea of this taking place after she’s been poisoned, and for the final irony to be that Chance has found someone whom he could love and love him back and his capricious demonstration of freewill has destroyed that.
Keep working on it, and think more about your audience with future rewrites. Good luck!