I expected Skyhill to brush it off, but he nodded slowly. "That has been a problem," he admitted, "and we haven't quite beaten it. Some people are totally unaffected by SPISES-negatively, I mean-while others cannot tolerate it at all. We've had to screen our volunteer subjects very carefully, and make sure we show our clients how to handle the screening as well. Of course, we're trying to fine-tune the technology so anyone can use it."