The robot, known as a Tug, edges closer and closer to me at the elbow of the L-shaped corridor and stops. It turns its wheels before accelerating through the turn, then suddenly halts once again. Josh, the photographer I’d brought along, is blocking its path, and by way of its sensors, the robot knows it. Tug, it seems, is programmed to avoid breaking knees.

This hospital—the University of California, San Francisco’s Mission Bay wing—had opened four days before our visit. From the start, a fleet of Tugs has been shuffling around the halls. They deliver drugs and clean linens and meals while carting away medical waste and soiled sheets and trash. And by the time the fleet spins up to 25 robots on March 1, it’ll be the largest swarm of Tug medical automatons in the world, with each robot traveling an admirable average of 12 miles a day.

The whole circus is, in a word, bewildering. The staff still seems unsure what to make of Tug. Reactions I witness range from daaawing over its cuteness (the gentle bleeping, the slow-going, the politeness of stopping before pancaking people) to an unconvincingly restrained horror that the machines had suddenly become sentient. I grew up in Silicon Valley and write for WIRED and even I’m confused about it. The whole thing is just weird.