A small, Swedish startup called Wheelys is trying to match Amazon at creating cashier-free stores with automated checkout. But after rolling out the first test store in Shanghai earlier this year, the company is now moving on to a completely new, if a bit awkward, idea: an autonomous store that’s perpetually roaming the streets, called Moby Mart.

Moby Mart is a mobile store on wheels. It’s about the size of a small bus, and the idea is that eventually it will use artificial intelligence and computer vision to navigate city streets. (The current prototype is controlled by humans.) It carries some basics, like fresh food, as well as things like sneakers and magazines. Like Amazon Go, the retail company’s recently announced autonomous store concept, there are no lines, no cashiers, and no cash. You just scan the items you’re taking, and the Moby Mart app automatically handles the transaction for you.

Now, this is where things get tricky with Moby Mart. Wheelys (which has partnered with a Chinese university to bring the tech to life) says that the store will be able to drive to warehouses to restock itself, and hints that customers could be able to summon the stores, too. There’s also a drone delivery component. But right now, there’s no detail on how Wheelys plans to build out or support any of these ambitious ideas.

A mobile store could possibly help serve underdeveloped urban areas with limited access to quality food or other basic necessities. But it frankly feels like an idea that’s best suited as a prop in a sci-fi movie. Wheelys says it will test the prototype store in Shanghai, and that the company plans to produce more of them in 2018.