Perhaps the clues are to be found within the pages of a book entitled Beyond The Deep that chronicles the breathtaking 1994 San Agustin Expedition as told from the perspective of Bill Stone and Barbara am Ende.

Much of the information was gleaned from their logbooks, diaries, and recollections, as well as from dozens of interviews conducted by their co-author Monte Paulsen.

In 1977, 1979 and 1981 cave divers were unsuccessful in exploring the San Agustin sump or the underground tunnel that was flooded entirely with water. This sump is the deepest point in a cave known as Sistema Huautla, Oaxaca, Mexico.

Many of the difficulties were the result of using traditional equipment as well as the inability to effectively transport the supplies and gear necessary to accomplish this incredible feat.

In 1994 international exploring expert Bill Stone completed the construction of an closed cycle life support system or, as he termed it, a "rebreather." This piece of apparatus was called the Mk-ll. This would permit the cavers and divers to explore the San Agustin Sump far longer than anyone was able to accomplish in the past. It was Stone's contention that the problem was primarily a technological challenge. Once this was overcome, the rest would fall into place.

The next step entailed the meticulous organization of the various components of the team. There was expedition leader Stone, six dive team members, 35 support team participants and five members of the photo team. These individuals wanted to "place their own boot where no one had before." According to Stone, "every member had made enormous personal sacrifices in the pursuit of this elusive grail. They'd left family behind for a third of a year; had trained relentlessly for two years just to get there; had gone deeply into debt; and were subjecting themselves daily to physical hardships."

Why do it? Perhaps Stone sums it up when he asserts, "after so many years of struggle, he'd found the route, the secret doorway to the gaping, unexplored beyond."

One of the shortcomings of the book is the extensive use of technical jargon. The authors did indicate in the introduction that they have substituted common words for technical jargon wherever possible. However, unfortunately, far too often I had to refer to the glossary at the back of the book to understand a paragraph or sentence. No doubt this deflated some of the suspense of the saga.