“Nancy, Please” as a character study that reliably builds up tension incorporates some very strong performances. In fact, acting performances make this new feature film by newcomer Andrew Semans.

Paul (Will Rogers) plays a believable (and believably) unraveling academic who’s left his dissertation’s source text at his previous apartment and cannot seem to get it back. His motivations for directing all his frustration at Nancy (played by Eleonore Henricks; she’s the former roommate who refuses to return the book to him after he moves out of their apartment) are a little obscure. Narratively, it feels like the other shoe never really drops. Something happened between these two once upon a time,—that much is clear—but we never find out what.

Many events that happen or are hinted at aren’t ever resolved: for instance, Paul steals a polaroid he finds of a naked Nancy and stuffs it in his pocket, but we never find out why he stole it, what he did with it and whether Nancy realizes that it’s gone. However, despite these frustrating plot holes, “Nancy” is effectually disturbing and the performances of supporting characters such as Paul’s girlfriend (Rebecca Lawrence) and her Yale best friend (Santino Fontana) help buoy up what might otherwise be a very flimsy movie (see the rest of our Tribeca coverage).