There exist another dimension called The Empty World. It's very much like ours, in fact it seems to have been identical up until a few weeks ago, but it always seems that way. If you go there today, it was identical in late february, and if you go there this october, it'll have been identical until september.
It's empty, as you might guess. There's no humans, and no animals bigger than a cockroach. The sky is grey, and it slowly rains ash. It's colder than our world by a bit, enough to require a jacket even in summer. The streets are empty, the cars parked neatly in their garages or in lots, but they're all empty and abandoned, their doors locked like they expect their owners to return any minute now.
The newspapers left on stands don't mention any oncoming disaster. We have no idea what the TV or internet would have said: the power is out. The power is very, very out. Not just the grid, but batteries are drained. The cars won't start, the emergency lights are out, and anything with solar panels seems to be getting less energy than you'd expect, even with the perpetually overcast sky.
It's a very silent world, like the calm after a snowstorm. Sounds don't seem to echo as much as they should, nor does sound seem to travel as far. The radio spectrum is empty except for static, there's no one transmitting on any frequency.
There's fewer fires than you'd expect. Even places you'd expect to soon catch fire without human intervention are still standing, undamaged. Campfires can be lit but with difficulty: something is keeping them from burning as they should. Even if you pour kerosene on a campfire it'll barely grow, it's like something sucked the energy out of everything.
All the locked buildings are still locked. Alarms don't sound if you break in (understandable, given the power situation), and of course no one comes to investigate. So The Empty World is your oyster: you can break in wherever you want (provided you can physically do it: some doors are pretty hard to pry open even with tools), take whatever you want, and bring it back here.
Everything resets when you leave. You always enter The Empty World like it's your first time there, like this just happened and you're late to the party... but the party keeps getting rescheduled. You can even take something multiple times if you want.
When you enter The Empty World you get there at the same relative position as you are on this world. If you're in New York, you show up in the empty New York. If you're in Topeka, you show up in empty Topeka. So you have to travel around this world to get to where you want, and you can't just appear in the middle of a bank vault... unless you break into the vault from this world. (So it's great if you work at a bank and want to steal from your employer without repercussions, but not so useful otherwise).
You don't just have to take things, you know. You can take computers and files and books and diaries. You will have to deal with recharging laptops and breaking through any security when you get back, but it's doable.
So, imagine you've just gotten access to The Empty World. What are you going to do with it? What will you take, and where will you go?
