I learned today -- just 40 minutes ago, in fact -- two things.
1. The Ground Fault Circuit Interrupter (GFCI) plug we have hooked into a circuit down here is indeed working correctly.
2. Our sump pump is shot.
Here's how the story went:
At around 5:05 AM, the entire downstairs family room shut up, save for the lamp in the corner. This happened because the GFCI plug that keeps the circuit from frying got tripped by a sudden surge of energy.
Now, this plug is the one to which our modem and router are connected, so that knocked me right offline. Not knowing what to do, I asked the electrician of the house (who was just about to go to bed) what he thought happened. One thorough investigation (through process of elimination) later and we found our culprit.
As it turns out, the sump pump we have -- which is connected on this circuit -- gave out after two years of barely doing anything. Apparently, it has water in it, causing it to short circuit, so any time it tried to run, the GFCI plug would trip and, you know, prevent the whole circuit from frying.
All I have to say is God bless GFCIs.