I agree with Mike – this sounds fun.

I’ll give this a crack…

I kept wanting to say “In a post-apocalyptic world” or “Set in the future” ha. But there’s no sign of this being set in the future.

After a plague devastates humanity, a thief must stop a megalomaniac from taking the world’s depleting resources.

Could do “team of thieves” perhaps?

I love the idea of the setting/the bottom floor of a skyscraper but perhaps not necessary in a logline?

“- only to find the plague never left.” – I wanted to add. But… I dunno… There’s plenty of stakes here. The stakes are high – it’s the survival of the world.

I traded “mad overlord” with “megalomaniac” – as it’s one word. I dunno if he’s a tyrant. Could potentially use mad tyrant perhaps?

I also cut – “for himself.” at the end. I mean he’s clearly up to no good ha.

Anyways – that’s what I’ve got.

Good luck!