They call me the Master of Robots—or at least they should. I grab a flat package, hold its barcode under a red laser dot, and place it on a small orange robot. I hit a button to my left and off zips the robot to do my bidding, bound for one of more than 300 rectangular holes in the floor corresponding to zip codes. When it gets there, the bot engages its own little conveyor belt, sliding the package off its back and down a chute to the floor below, where it can be loaded onto a truck for delivery.

This is not an experimental system in a robotics lab. These are real packages going to real people with the help of real robots in Amazon’s sorting facility of tomorrow, not far from the Denver airport. With any luck, my robot friend and I just successfully shipped a parcel to someone in Colorado. If not—well, blame the technology, not the user.

Seen from above, the scale of the system is dizzying. My robot, a stubby mobile slab known as a drive (or more formally and mythically, Pegasus), is just one of hundreds of its kind swarming a 125,000-square-foot “field” pockmarked with chutes. It’s a symphony of electric whirring, with robots pausing for one another at intersections and delivering their packages to the slides. After each “mission,” they form a neat queue at stations along the periphery, waiting for humans to scan a new package, load the robots once again, and dispatch them on another mission.

Matt Simon covers cannabis, robots, and climate science for WIRED.

You don’t have to look far to see what a massive shake-up this is for the unseen logistics behind your Amazon deliveries. On the other side of the building are four humans doing things the old way, standing at the base of a slide flowing with packages. Frenetically they pick up the parcels, eyeball the label on each, and walk them over to the appropriate chutes. At the bottom of the chutes, yet more humans grab the packages and stack them on pallets for delivery. It’s all extremely labor-intensive and, in a word, chaotic.

Amazon needs this robotic system to supercharge its order fulfillment process and make same-day delivery a widespread reality. But the implications strike at the very nature of modern labor: Humans and robots are fusing into a cohesive workforce, one that promises to harness the unique skills of both parties. With that comes a familiar anxiety—an existential conundrum, even—that as robots grow ever more advanced, they’re bound to push more and more people out of work. But in reality, it’s not nearly as simple as all that.

If only the Luddites could see us fulfilling online orders now.

This Colorado warehouse is, in a way, a monument to robots. It’s not one of the Amazon fulfillment centers you’ve probably heard of by now, in which humans grab all the items in your order and pack them into a box. This is a sorting facility, which receives all those boxes and puts them on trucks to your neighborhood. The distinction is important: These squat, wheeled drives aren’t tasked with finely manipulating your shampoos and books and T-shirts. They’re mules.

Very, very finely tuned mules. A system in the cloud, sort of like air traffic control, coordinates the route of every robot across the floor, with an eye to potential interference from other drives on other routes. That coordination system also decides when a robot should peel off to the side and dock in a charger, and when it should return to work. Sometimes the route selection can get even more complicated, because particularly populous zip codes have more than one chute, so the system needs to factor in traffic patterns in deciding which portal a robot should visit.