OBLIVION The Mystery of West Point Cadet Richard Cox By Harry J. Maihafer Brassey's. 256 pp. $24.95

Ever have the urge just to walk away from it all? Close the door, lock it, hit the bricks and never look back? Forty-six years ago, third-year West Point cadet Richard C. Cox did exactly that. The date was, to put it militarily, 14 January 1950. The clean-cut 21-year-old, who'd been in the Army before qualifying for the military academy, spent part of the afternoon watching Army's basketball team beat Rutgers, and that night signed out to go to dinner with a male civilian he'd been seen talking to after the game. He told his roommate he'd be back early. That was the last time, from that day on, that anyone at West Point or from his home town of Mansfield, Ohio, saw Richard Colvin Cox.

What made Cox's vanishing act even more puzzling was that he'd left few if any hints and nary a clue. Up to the day he disappeared, he'd been in regular contact, by phone and by mail, with his widowed mother and his fiancee, neither of whom ever heard from him again. Both told investigators there was nothing in his recent behavior to indicate unusual stress or a desire to leave West Point.

Regarding the mysterious "civilian friend," his roommates told the officer-in-charge that "Cox had gone on Dining Privileges shortly after six, having been invited out by a man he'd known in the army in Germany. The same man, they said, had also visited Cox the previous weekend. . . . {But} they had gathered from Cox's few remarks that he didn't really care for this guy and had even complained that the man was taking up too much of his time. Cox, they said, had described his visitor as pretty much of a braggart, a bad apple who even boasted about having murdered some woman in Germany." This information caused initial speculation to center on the possibility of foul play, rather than desertion, but no body turned up.

As the days following Cox's disappearance turned into weeks and months, the search conducted by the Army's Central Intelligence Division (CID) and the local police was joined by the FBI. Still no trace of Richard Cox. However, each time attention to the case seemed about to wane, something would happen to reignite the flame of public interest.

A letter Cox had written to a female friend in Germany in December 1949 was "returned to sender" and hurriedly opened, but its contents, while intriguing -- after mentioning that he was studying Russian, he asked, "What is the Russian situation in Lichtenfels and vicinity? . . . Im very interested in the Russian situation" -- led the investigators no further. In 1954, there was a purported sighting of Cox in the restaurant of the Greyhound bus station in Washington. And, of course, there were letters from correspondents who claimed to know where Cox was (one said he was being held in Greenwich Village as a "love prisoner"), or what had happened to him, or both. In 1957, when the State of Ohio declared Richard C. Cox legally dead, the FBI had no fresh leads.

"Understandably," Harry J. Maihafer writes, "the army officials believed they were finally justified in putting the Cox mystery behind them, and they doubtless believed they had heard the last of Richard Colvin Cox, the missing West Point cadet.

"They were wrong."

Enter Marshall Jacobs. In 1985, nearing retirement as a Florida high school teacher, Jacobs, who'd been raised in the West Point area and was a trained researcher, decided to spend his retirement years "finding out what happened to Richard Cox." And it appears that he has. In 1995, Jacobs looked up Maihafer, a military historian (West Point Class of 1949) whose books he admired. He begged Maihafer for a meeting.

Maihafer writes, "Marshall Jacobs turned out to be personable, articulate, and the owner of a fascinating story." The admittedly obsessive researcher told the writer "what he had learned during his extensive, labyrinthine, eight-year investigation. . . . Personally, I've always been a fan of mystery stories. Now I was hearing a tale that rivaled the best fiction. It had all the elements -- international intrigue, murder, coverups, dramatic surprises, and dogged detective work."

The result of their collaboration is "Oblivion," a fitting tribute to the work of Jacobs, and a (fairly) satisfying coda to the saga of Richard Cox. If I can't go so far as to call this book a page-turner, I can say it held my interest right up to the very end -- no, especially at the very end.

I'm tempted to tell you what Jacobs found, but I'm afraid that if I did I might disappear. The reviewer writes frequently about true crime and the law.