The candidates congregated at lunch and over dinner. The men organized trips to the Alamo, in downtown San Antonio. York kept away from those macho gatherings and tried not to let herself get depressed.

On the first morning of the tests, she had to start at six o’clock Texas time, which was 4 A.M. Berkeley time. So that was the first of her handicaps. She couldn’t even get a coffee; she was supposed to fast until lunch for the purposes of the tests.

The tests were going to last all week.

The first test was for glucose tolerance. Blood was drained from her arms while she forced down incredibly sweet glucose liquid.

Then she was subjected to eye tests: there was an Ishihara color-blindness test, and a photograph of her retina taken by a flash blazing into her eye. She had to drink a liter of lukewarm water, after which a weight was placed on her eyeball, to measure the fluid excreted.

There were internal medicine tests. She had to lie for an hour inside a Faraday cage, a metal box that excluded electric fields, while a cardiogram was taken. York felt like a chimpanzee in a zoo. Then she was strapped into a device fitted with a parachute harness, designed to hang her while the blood pooled to her feet. She had to hyperventilate until blackout symptoms began to show, little dots darting around her vision.

Then — brutally quickly — she was given a Master heart test, where she climbed and descended stairs while holding electrodes to her chest. At the end of the test she had to fit her lips around a mouthpiece so her exhaled carbon dioxide could be collected for volume measurements.

There were tests of her vestibular system, the balance apparatus of her middle ear. Hot and cold water was poured into her ears to confuse her vestibular canals, making her dizzy. Doctors peered into her eyes, watching how long it took her eyelids to stop flickering.

Later, she was told to walk in a straight line through a darkened room. The idea was to test for vestibular imbalances. When the lights came up she found she’d drifted maybe a yard to the left of the room’s center line.

The tilt chair was another vestibular test. It looked a little like an electric chair, mounted on a rotating platform in the middle of a pitch-dark room. She was strapped into the chair, and electrodes were fixed to track her eye motion. The chair was spun around, once every three seconds, and tipped back and forth. Every so often they would reverse the direction of tilt and rotation. It was like a carousel ride, run by lunatics; every tilt made York feel as if she wanted to upchuck, but she was determined she wasn’t going to give those assholes that satisfaction.