A teenager and his kid brother spar with their mother's shady new boyfriend in this dramatic thriller from veteran British director Michael Apted. When her ex-husband remarries, Wendy (Teri Garr) feels despondent -- until she starts dating handsome, unctuous Sam (Peter Weller), an underemployed salesman with no shortage of big ideas. Excited to finally feel good about herself again, Wendy invites Sam to move in and offers to invest in his get-rich-quick schemes. None of this sits well with her sons, Jake (Christopher Collet) and Brian (Corey Haim), who remain unimpressed with Sam even after he convinces Wendy to buy Jake a motorbike. They're even less jazzed when Sam stops currying favor and turns disciplinarian even while pulling Wendy into his hard-partying lifestyle. Within a few months, Brian's on the verge of expulsion for picking fights at school, and even honor-role student Jake is mouthing off to his teachers. As for Wendy, she's too busy taking beatings and doing cocaine to notice that her family has fallen apart. It isn't until Jake gets wise to the industrial quantities of white powder squirreled away under the floorboards that he comes up with a plan to get Sam out of their lives forever. Although onetime Tiger Beat heartthrob Christopher Collet plays Firstborn's title role, the films' supporting cast is littered with actors whose stars would far eclipse his (Sarah Jessica Parker, Robert Downey Jr.) -- though in some cases only for a little while (Corey Haim).
~ Brian J. Dillard, All Movie Guide