Perfect, they look good on you! Now, watch this.

[ Once the bar is clean as a whistle, bone-dry, and there's no trace at all of the horseradish, out comes the luminol. She gives the bar just a couple of good sprays, and lets it sit for a second... ]

It's too bright in here to see it without them, but if you put on your glasses, you should see exactly where the sauce was.

[ In bright, bright blue, no less! ]