Help, my logic board is possessed!
Macbook Pro Retina was stuck in boot chime and unresponsive.
The repair was easy, but the laptop must have come from a company known as "Mindbody" as I keep getting prompts to let the laptop enroll me in some DEP.
First boot had the "question mark folder" on the screen, then asked if I wanted to "update from the network", which was the only choice presented with pressing the option button. The next boot I was able to use an installation USB jump drive to install OS X High Sierra. Laptop is lightning fast with the aforementioned prompt the only hassle. I'm sure I'll find the solution to get rid of that eventually.