A quick refresher: The first installment, directed by Del Toro, introduced viewers to the world of kaiju (Godzilla-like monsters) and jaegers (Gundam-like robots). An interdimensional portal at the bottom of the Pacific Ocean, dubbed "the breach," was letting these kaiju mercilessly terrorize coastal cities, and so Idris Elba, starring as General Stacker Pentecost, led a team of pilots to victory in an epic underwater showdown that became known, fittingly, as the Battle of the Breach.
Uprising, directed by DeKnight and co-written with Emily Carmichael, Kira Snyder, and T.S. Nowlin, picks up 10 years after that battle, with the world enjoying some semblance of peace. John Boyega gives a tremendous turn as Jake Pentecost, Stacker's son, who, in the absence of his late war-hero father, lives like a fusion of Rey and BoJack Horseman, a hard-partying rebel scavenging junk jaeger parts for profit. It's not long before he finds trouble alongside Amara Namani (Cailee Spaeny), a jaeger fangirl who's toyed with building her own bot, getting arrested and shipped off to the Pan-Pacific Defense Corps to instruct new recruits alongside his old co-pilot Nate Lambert (Scott Eastwood). It's there that Jake learns of a new jaeger program, one that combines cloned kaiju cells leftover from the war with the mecha-tech to create massive remote-controlled drones.
Why? Well. Everyone's a little unsure, honestly. Where Del Toro worked to mesh themes of humanity with ambitious set pieces in the first movie, DeKnight's sequel drags like a long string of plotty excuses made to get these bots back out of the garage and battling extraterrestrial baddies. Which is fine, the movie just lumbers to get us to that point, with not enough real tension and drawn-out focus on a rogue jaeger.
Things start to get interesting later, when Uprising reveals that Dr. Newton Geiszler (Charlie Day, back from the first) has been connecting to kaiju brains in secret, lured back to the Drift almost as a junkie. So while the aliens have been shut out of the human dimension, they still have a link to earth and a vehicle with which to sow mayhem.