"The signs on Bell’s door read “J.Bell” and “M.Bell.” I knocked and was invited in by Bell. He looked about the same as he had the last time I saw him, a couple of years ago. He has long, neatly combed red hair and a pointed beard, which give him a somewhat Shavian figura. On one wall of the office is a photograph of Bell with something that looks like a halo behind his head, and his expression in the photograph is mischievous. Theoretical physicists’ offices run the gamut from chaotic clutter to obsessive neatness; the Bells’ is somewhere in between. Bell invited me to sit down after warning me that the “visitor’s chair” tilted backward at unexpected angles. When I had mastered it, and had a chance to look around, the first thing that struck me was the absence of Mary. “Mary,” said Bell, with a note of some disbelief in his voice, “has retired.” This, it turned out, had occurred not long before my visit. “She will not look at any mathematics now. I hope she comes back,” he went on almost plaintively; “I need her. We are doing several problems together.” In recent years, the Bells have been studying new quantum mechanical effects that will become relevant for the generation of particle accelerators that will perhaps succeed the LEP. Bell began his career as a professional physicist by designing accelerators, and Mary has spent her entire career in accelerator design. A couple of years ago Bell, like the rest of the members of CERN theory division, was asked to list his physics speciality. Among the more “conventional” entries in the division such as “super strings,” “weak interactions,” “cosmology,” and the like, Bell’s read “quantum engineering.”"