Hardcover : by Wayne Warga (Arbor House: $15.95; 274 pp.)

Atraditional device employed to open suspense novels is for a seemingly innocuous event to lead to the gradual uncovering of evil doings. While attending a book fair in Los Angeles, rare-book dealer Jeffrey Dean leafs his way right into an international plot to assassinate Ronald Reagan.

A John Steinbeck first edition--unmistakably once owned by Dean--now bears a bogus authorial inscription. The book dealer’s attempt to identify the forger initiates a harrowing two-week period during which his files are ransacked and several attempts on his life are made.

Such a leap from staid bibliopoly into primal political terrorism requires the suspension of disbelief almost invariably demanded by what is an inherently flamboyant genre. Author Wayne Warga affords a smooth transition into this tightly constructed thriller, whose digressions will appeal to the sophisticated reader.

“Hardcover’s” cast of characters includes an oil millionaire who collects books on an epic scale, two CIA men who are working against each other, an Arab book dealer from London with unsavory Libyan contacts and a still-waters-run-deep type described by the author as a “man who seemed forever destined to work in the wrong museum, a curator without portfolio for sale.”

There is also an attractive woman who becomes involved with Dean--on the case and in bed. Not the least of Warga’s talents is his ability to create bedroom scenes that are at once sensual (no heavy breathing) and concrete (no Masters & Johnson making love by the book). Not so well-executed is a subplot abandoned in mid-book concerning Dean’s relationships with his 10-year-old son and divorced wife.

By way of bonus, the author demonstrates his insight into the internal workings of a CIA team, contrasting the low-keyed professionalism of a seasoned agent to the fumbling of a quondam courier whose duplicity is largely confined to the padding of his expense account.

Better yet is the added element that keeps “Hardover” from being just one more accomplished thriller--Warga’s knowing depiction of the rare-book milieu in which the novel is set. The buying and selling of books in Jeffrey Dean’s area of specialization, contemporary literature, is shown for what it is, one of the purer if riskier forms of entrepreneurship. Dean embodies the requisites necessary for success in a highly competitive business, where judicious money management of the kind exercised by a good high stakes poker player is of vital importance. And we are shown by conspicuous example that Dean is well read enough to form his own literary judgments. Such literary expertise enables him to function confidently as a book dealer in a bibliographical no-man’s land where a classic can be accurately defined as a book that is a generation old.