A mysterious scientist recruits couples to test her "Strength Increase Serum" – but oddly enough it only seems to work on the women. And girl, does it ever work! While nerdy Jacob and buff Mike see no benefit, tiny Emily and fitness instructor Sarah find themselves growing bigger, more muscular, and vastly stronger! Sarah's always wanted to be strong, so her bulging muscles and new power are like a dream come true, but Emily's not quite so sure...