Here's my nineteenth Inktober illustration, for the prompt "loop".
I sat down at my iPad not knowing what I might draw. I thought about doing a mobius strip, or a cartoon character running on a conveyor belt. I had an idea about doing an infinite fall through a set of interconnected portals. I thought about somehow drawing the feedback loop you get through a mic and a sound system.
And then, after a moment of thought, a lightbulb appeared above my head. And then I draw this!
Time-lapse video below: