For a few moments I'd been carried along by Jocasta's enthusiasm. But suddenly the rush totally evaporated. The logical structure we'd built just didn't hang together. Again, I had the inescapable feeling we were missing something crucial. We had most of the pieces of the jig- saw puzzle, and we'd put them together to form a picture. But it felt like we'd hosed it by forcing a couple of pieces into spots where they just didn't fit. I shook my head.