The cute concept of the original 1995 Toy Story, the first ever Pixar feature, is the stuff of many a kid’s childhood fantasy. What if, when you exited the room, your toys came alive and had their own rich thoughts and feelings? The first film followed a rivalry between Woody and Buzz Lightyear (Tim Allen), Andy’s new favorite, and the sequels were both concerned with the toys’ fears of mortality and aging, reflected in Andy growing up and Woody worrying he’d lack a purpose if he wasn’t played with. At the end of Toy Story 3, the departure of Andy was a tear-jerking goodbye, but the arrival of Bonnie suggested the fun could last forever.

While that could have been the end for the franchise, Toy Story 3 made $1 billion at the worldwide box office, and so here we are. Luckily, Toy Story 4 (written by Andrew Stanton and Stephany Folsom and directed by Josh Cooley in his filmmaking debut) has some very heady things in mind. Sure, the fun can last forever for Woody, but that’s because he’s functionally immortal—as long as nothing ever rips his stuffing out, he can exist eternally, thanks to whatever toy magic is powering him. More than anything, the film is about him arriving at new insights about this immortality as he reflects on the creation of Forky, a plastic creature who can think and speak simply because his creator (a kindergartener) pasted him together in class.

That’s not to suggest that most of Toy Story 4 involves Woody and his pals sitting around their bedroom and debating the writings of Descartes. The plot is, as usual for these films, an extended action caper, set mostly at an amusement park that Bonnie’s family is visiting on vacation. But the adventure is spurred into motion by Forky jumping out of a car window because he knows that he’s a creature made of trash and thinks he deserves to die. At multiple points, Woody and Buzz discuss their own “inner voices” (their consciences) and how those drive them to make selfless decisions, like rescuing an existentially compromised living spork. Toy Story 4 can have all the fun it wants, and it does, but it also throws these deeper concepts around with abandon.

Woody’s mission to rescue Forky involves convincing the little fella that toyhood is a noble calling, and that the joy he brings Bonnie is enough reason to keep on living. That’s the essential concept that drove all the other Toy Story films—the powerful, nostalgic bond between a child and their most beloved possessions. But as Woody explores the amusement park and its environs, he rediscovers Bo Peep (Annie Potts), one of Andy’s old toys, who was given away years ago and was absent in Toy Story 3. She’s now leading an independent life free of her owner, along with a motley crew of new characters like the Canadian action figure Duke Caboom (a masterfully dry Keanu Reeves) and the wisecracking plush animals Ducky (Keegan-Michael Key) and Bunny (Jordan Peele).