The machinery is broken.. has seized up, or maybe… the engine’s burned out!

I have no idea what happened to it, I’ve examined it and everything seems fine as far as I can tell, but honestly I have no idea what I’m looking at, or how to diagnose the problem. Everything seems to be in working order, and no parts are missing, or loose, wire harnesses are attached, belts are intact, fluids are full, it has plenty of fuel… the starter turns over but it doesn’t engage. Maybe there’s no combustion, no spark, no synthesis…

The stress is insurmountable…