Allen, a brilliant biochemist who’s unlucky in love, devises a compound to turn polyamorous leanings into monogamous ones. He injects his best friend, Marcia, to help her overcome her habit of cheating on her wife, Sarah.
But when Sarah finds Marcia’s new fixation on her to be suffocating, Marcia insists Allen give Sarah a dose too. However, Allen’s intervention takes an unexpected turn as Sarah falls for him, who must team up with a rival scientist, Lisa, for whom he’s falling, to set things right.