WEST POINT, N.Y. - It was a little before midnight when the howling mob of pimply-faced plebes burst into his room. Three or four wild-eyed goons jumped on his chest and the others duct-taped his wrists together. Someone produced an electric razor and gouged out a strip of his hair and someone else tried to scrawl "Beat Navy" in his scalp with a blue marker, only the marker skipped and it turned out more like "be nay," like some kind of weird Zen koan. Then suddenly they were gone, their frenzied laughter echoing down the barracks hallway.

When Josh Hellwig finally freed himself and stared into the mirror, he looked like a man who'd wandered into a freshly painted ceiling fan. Forced to shave his entire head to cover up the gouges, the electrical engineering major from Wisconsin muttered, "There will be retaliatory action," even as a smile played across his features.

As a chilly autumn grips the highlands of New York's picturesque Hudson Valley, Josh Hellwig finds himself deep behind enemy lines.

A midshipman 3rd class (junior) at the U.S. Naval Academy, he's here at the U.S. Military Academy with eight other mids as part of the annual semester-long student exchange program between the service academies. Although Hellwig and his fellow mids stand out in their "working blues" or "summer whites" amid 4,000 cadets in grays or bdu's (battle dress uniforms), during a normal week they live in the austere, fortress-like barracks, attend classes and form up for the noon march into the cavernous mess hall without incident.

But this is not a normal week. This is Navy Week.

At noon tomorrow at PSINet Stadium, the Army and Navy football teams renew their historic rivalry, meeting for the 101st time. Which means in the days leading up to the big game, these mids at West Point find themselves victims - and instigators - of all manner of pranks and verbal harassment, most, if not all, of it good-natured.

In some ways, the high spirits sur- rounding the game stand in stark contrast to what is produced by the teams on the field. Football at the service academies has fallen on hard times, and the glory days of Heisman Trophy winners Glenn Davis, Doc Blanchard and Pete Dawkins of Army or Joe Bellino and Roger Staubach of Navy, when the academies produced some of the top teams in the country, seem long ago, indeed.

Navy is winless this season at 0-10. Army is 1-9, its lone win over weak sister Tulane. But, as always, a victory by either over its arch rival will take the sting out of a miserable season. The Game, therefore, looms large in the minds of the cadets and midshipmen - and so do the pre-game high jinks.

Just two hours after enduring that unfortunate haircut, Josh Hellwig slips out of his barracks and joins five other midshipmen on a covert operation. Dressed in black and lugging shopping bags, they sprint across the dark parade grounds and creep up to the elegant home of the academy superintendent, Lt. Gen. Daniel W. Christman.

Quickly, Navy blue and gold crepe paper is hung from the porch. Navy balloons are tied to the railings. Rolls of toilet paper thud loudly against the porch roof and trail down over the eaves. (Amazingly, no lights inside click on. Apparently, the superintendent and his family are not just sleeping, but are also heavily anesthetized.)

Finally, the ultimate act of sabotage: wielding screwdrivers, the mids rearrange the signs hanging from the window boxes to say "Go Navy!" and "Beat Army!" In the morning, the academy will awaken and there, out of the mists, the "Supe's" house will come into view, desecrated with Navy colors - at least until the mess is quickly cleaned up. The midshipmen will cackle and boast about the ridiculous ease with which they carried out their night-time operation. The cadets will vow revenge.

"Bring it on! I'm waiting!" cries Blythe Oraker the next day. Oraker, an ocean engineering major from Bremerton, Wash., is one of three female midshipmen in the exchange program and the de facto ringleader of the raid on the Supe's house. Right now she and Josh Hellwig are wearing their "white works" and standing amid an army of cadets in bdu's inside the mess hall, under a gigantic color mural depicting famous battle scenes throughout history.

"This is actually for going to [phys ed] class," says Hellwig of their baggy, glaring-white uniforms. "We wear it 'cause it's kind of obnoxious. When the guy in the barbershop sees me, he always says, 'I'll take two scoops of vanilla.'"

Like the menacing horsemen wielding sabers in the mural directly over their heads, though, Hellwig and Oraker seem more than capable of holding their own in a good scrap.

Practiced pranksters

There is a long and glorious tradition of pranks and assorted mischief associated with the Army-Navy game. Teams of midshipmen have infiltrated West Point under cover of darkness and painted "Beat Army" on monuments. Army cadets have scaled the roof of Bancroft Hall in Annapolis and dumped bags of flour on black-uniformed midshipmen below.

One year, a Navy helicopter dropped thousands of blue and gold ping-pong balls on the Corps of Cadets during noon formation. The Navy mascot, a goat, and the Army mascot, a mule, have been kidnapped by the other side quite a few times, although mascot-kidnapping has been officially banned since the multiple kidnappings of four mules in 1991.

Eccentric billionaire H. Ross Perot, an Annapolis graduate of the class of '53, was involved in one of the most memorable pranks ever at West Point.

According to the book "The Long Gray Line" by Rick Atkinson, Perot somehow enlisted the aid of the Army chaplain on the eve of the 1975 game. Along with the academy bell-ringer and a friend, Perot gained entrance to the West Point chapel shortly after midnight, "with embers from the pep rally bonfire still glowing on Abner Doubleday Field" below. The three men made their way to the belfry, where there "sat a contraption with a dozen wooden handles. Slender cables connected the handles to seven tons of chapel bells in the loft overhead."

"At 12:30 a.m.," the book continues, "the tranquility of the Hudson Valley was shattered by the deafening peal of a tune that turned any decent Army man's blood to froth: Anchors aweigh, my boys, an-chors a-weighhhh!

"This unholy din was followed by 'The Marine Hymn' - From the halls of Montezuuu-ma, to the shores of Tripoli - and the obnoxious trill of 'Sailing, Sailing.'

"Within minutes, hundreds of cadets raced up the hill from the barracks. Cursing and shrieking, they stormed into the chapel like avenging Crusaders, vowing to smite the interloper. "Perot, who had locked the gate to the belfry, taunted them briefly before surrendering. The cadets manhandled him out of the chapel to the north portico, where they surrendered the intruder to the military police."