★★★ ½

You’re free to entertain any theory you want about where babies come from, but it’s particularly lovely to envision a conveyor belt in the clouds, where cute little babies (and their cute little tushies) are bathed and powdered and pacifiered in preparation for their gentle descent into the arms of loving families. And who runs this place? Every once in a while, a humorless baby who’s uninterested in cooing and gurgling comes down the line, and the only solution is to shunt all of them into managing the whole stork factory. But due to a bureaucratic mix-up, one of these type-A newborns (dressed in sharp Armani with a union-suit flap over the butt) is sent to the family of seven-year-old Tim (voiced by Miles Christopher Bakshi), who isn’t happy that this demanding interloper has ruined his status of being an only child. His worst suspicions are confirmed when he hears a gruff, very un-infantile voice (Alec Baldwin’s resonant Long Island rasp) emanating from the baby’s room, bragging on his Fisher Price phone about how the usual sleep deprivation and hunger strikes are making the adults putty in his hands.

The smug, petulant, manipulative, entitled, and easily enraged boss-from-hell Baby is the best part of this movie, echoing the thoughts of older siblings (and parents, if they’re willing to admit it) that no matter how cute they are, a bundle of joy is still a bundle of you-know-what to care for. (Baldwin and his recurring role impersonating CEO-turned-POTUS Donald Trump on Saturday Night Live will go uncommented on in this review, although there is a sly wink to Baldwin’s iconic work in Glengarry Glen Ross when Baby snatches a treat away from a playgroup flunkie and growls, “Cookies are for closers.”) Children’s movies and literature are usually afraid to tackle these murderous feelings of sibling rivalry, usually leaning on insincere “but I learned to get along” platitudes at the end. (The exception is Judith Viorst and Arnold Lobel’s picture book I’ll Fix Anthony, which is fondly remembered by jealous Gen-X siblings as a righteous mouthpiece for their rage over being displaced -- and maybe it’s also fondly remembered by the art department here, since all of Baby’s toys are of ’70s and ’80s vintage.) But the brothers’ path to mutual love -- and the understanding that love doubles when shared, despite Baby’s scoff that anyone who believes in sharing “didn’t go to business school” -- is honest and justified by their character arcs.

These babies are squeezingly, squee-inducingly adorable -- which makes their cartoon peril in some scenes a little too upsetting, especially for families that left the baby with a sitter to take an older child to the movies. A baby falls down the stairs in one of those circular walker things that the Consumer Product Safety Commission has declared causes tens of thousands of injuries a year! There’s also a chase in the backyard involving an explosion that’s never made clear if it was real or imaginary, and a cliffhanger denouement that might be too intense for tenderhearted kids. Perhaps the most heartbreaking scene is of the baby factory, with its Metropolis-like infinite rows of tots sitting at gray cubicles for all eternity. Mamas, don’t let your babies grow up to be middle managers.