Communications engineers duke it out through the telephone circuits--in a tele-technothriller about a plot to annihilate the nation's electronic call-switching systems. Acrophobic electronics wizard Andy Faulkner, dedicated AT&T employee and sole custodian of his profoundly deaf son Wayne, jumps to the right conclusions but goes after the wrong suspects when Silicon Valley's new, computer-controlled superswitch goes on the blink in the middle of a rainstorm. The trouble is traced to a call made from Wayne's TDD--the gizmo that lets the boy speak through the wires. Mr. Feferman, chief of security at the phone company, thinks the evidence is enough to take Andy off the job, but guiltless Andy refuses to take himself off the problem. With assistance from a pretty lineperson whose father is one of Andy's chief suspects, Andy puts gigabytes of data through his home computer and turns up suspicious dialing patterns that involve Stanford University's telecommunications lab and a disgruntled Stanford rejectee who calls him or herself ``Interrupt.'' Just as Andy starts to decode the evidence and understand that the wonderful electronic switches have been programmed to self- destruct, ``Interrupt'' kidnaps Wayne. Everything boils down to figuring out when the circuits will go haywire--after which Andy can track down his son, catch the culprit, and deal with his lifelong vertigo. Mildly tense first novel. Electronically impaired readers will find themselves at times overburdened with technodata.