I have a love/hate relationship with movie trailers. They can get me excited to see an upcoming film, but I often feel like I’ve seen a complete synopsis of the movie and perhaps all the best bits. The first trailer I saw for Downsizing had me intrigued for what appeared to be a zany sci-fi comedy, but the second one irked me as it showed a shift in direction. Thankfully, co-writer (along with Jim Taylor) and director Alexander Payne left some surprises for the film, and Downsizing is an effective, thoughtful social satire that usually left me guessing as to what might happen next.

Matt Damon and Kristen Wiig star as Paul and Audrey Safranek, who live extremely average lives in Omaha, Nebraska. For years, they’ve been watching (from afar) the development of a new technology that allows for people to be shrunk down to a small fraction of their original size. After talking to old friend Dave (who has been downsized) at a high school reunion and then going on a slick sales-pitch tour of Leisure Town, a high-end community of five-inch tall people ensconced under netting in New Mexico, they decide to take the plunge. Their money will be worth many times its value in this tiny town, and they’ll also be helping the world reduce its use of resources. What could possibly go wrong?

Payne, who achieved such wonderful blends of humanity and social critique in films such as Election (1999), Sideways (2004), The Descendants (2011) and Nebraska (2013), again strikes a fine balance, allowing moments of absurdity to sober up quickly. Naming a gated downsized community “The Summit at Navajo Orchards” is brilliant on several levels, and the mix of humor, sadness and optimism helps Downsizing succeed.

Suspension of disbelief is vital to good science fiction, and Payne uses several techniques to achieve that. First, he chronicles the discovery and evolution of the downsizing technology for us and the characters to the point that, when Paul undergoes the procedure, it is routine to the point of being banal. Second, he avoids many of the tropes of the shrinking-man movie: no attacks from giant bumblebees or April rain shower floods.

Downsizing isn’t perfect. Though it’s nice to have a film change direction, at times it seems that even Payne and his actors aren’t quite sure where they want to go. But it does offer material for reflection, and that can be big.