Apparently our first fingerprinting, which was local, was just for our home study. When we submitted our i600a paperwork to the US government, we were instructed to also send payment for biometrics fingerprinting, and then wait until they sent us a time and date.
And so we found ourselves driving to Charleston, SC, early Christmas Eve morning. :-) Yes, the appointment we were given was at 8:00 am, and apparently the only place in the state you can be fingerprinted for this particular process is in Charleston, which is on the coast, 2 hours away from us. If you fail to keep your appointment, your packet is regarded as abandoned (and so also your $1000 that you sent them, I'd assume).
Traffic was clear, so we arrived early. Thankfully, they opened their doors at 7:35 and started getting people in right away. After we passed through a metal detector and our purses, etc., passed through the x-ray machine, we were able to fill out the necessary paperwork and get those fingerprints done.
One more thing to check off our checklist. :-)