The girl's prime was valid! Matt confirmed it over the phone in a flat voice, and asked what we should do now.

I got the girl out of bed, washed her face, dressed her up, and brought her to the warehouse. I sat her in front of the spiral and put a marker pen in her hand. Without saying a word, I extended the spiral along the wall as far as possible, and marked the end point as ten to the power of 200; I put a small question mark in that segment.

Matt and I sat down and let her work. At first she stooped in front of the question mark, her arms dangling. This lasted for at least half an hour. Then she wrote "1". Very slowly, she proceeded to write more digits, right to left, until she had written down a 200-digit number! This done, she stooped again and her arms dangled.

I sat her down on a chair and said, "We've done it!"

Matt was destroyed. It took two weeks to verify that fucking 200-digit number, and of course it was a prime!

All our machines, and Matt's vast experience, were no match for the innocent brain of a young disabled girl with no name.