As a Lance Corporal of Marines, there’s nothing worse than the day a Staff NCO summons you without telling you why. All you know is that you need to report to the company office, and that it’s probably not good. Generally speaking, as a Lance Corporal, there’s never really any good reason for you to be talking to a First Sergeant.
The SNCO encounter is the boss fight of the Marine Corps experience.
(To help you out if you’re not sure what is going on here, in the video game Elden Ring, boss fights a marked with a yellow fog door. Once you cross the threshold, the boss fight begins, and your butthole gets torn asunder.)