Lettering on the refrigerator-size office safe spells out "Fort Knox." Rex punches in a secret combination and swings open the dark-green door, retrieving Humphrey the camel, Bronty the brontosaurus and Princess the bear.

Carolyn grabs several more animals from her office, where they've been arrayed upon her desk and shelves. Scotty the terrier is wearing a tutu. She decides the tutu might look better on Happy the hippo.Together Carolyn and Rex corral all of the creatures immediately available upon a conference-room table and delight in their fuzzy, color-splashed mini-zoo.

"Everyone here thinks we're nuts," Carolyn laughs, "but we're having fun."

Yes, their hobby is an obsession, an addiction - "Beanie Baby mania" is Rex's diagnosis. But that isn't why he, Carolyn and Margaret, a co-worker in their downtown Salt Lake insurance firm, prefer to be identified only by their first names.

"People are actually breaking into houses and cars" and stealing the incredibly popular miniature plush animals, Carolyn says. Beanie Baby bandits have put caution, if not fear, into the hearts of collectors.

But that isn't stopping their quest.

"I just figured out how many I have: 382," says Carolyn, who keeps methodical tabs on them with a graphic spread sheet listing their names (from Ally the alligator to Zip the cat), the date of their official "birth" (as announced by Ty Inc., the manufacturer), how much she paid for them, their current market value among collectors and how many she has of each of the various beasts and birds.

"Rex has over 800," maybe closer to 900, she says. "And we've only been doing this since October."

"This is the hottest collectible in a decade," says Cassandria Parsons of the Recollections gift shop in the ZCMI Mall. "People come in here, pay $200" for a batch of Beanies "and they're smiling."

"It is said that the value of a `perfect' collection of Beanie Babies (unsoiled, crisp cardboard hang tags) is now more than $40,000," report Les and Sue Fox in "The Beanie Baby Handbook." "This is probably true, as the days of finding bargain-priced rarities are pretty much history."

The popularity of Beanie Babies, created by H. Ty Warner, spans age groups and, perhaps surprisingly, genders. They're cute and, at first sale, relatively cheap, ranging from $5 to $6 per toy. After that their value can zoom to as high as $2,000, $3,000 even $5,000 (the latter for Peanuts the elephant, says Carolyn, "and you cannot get it"). Referring to a checklist pulled from the Internet, Carolyn counts 82 Beanies on the market. Another 57 have been "retired" - a strategy among makers of collectibles like these; in fact, Ty Inc. plans a major retirement announcement on May 1.

"I could sell 2,000 in a day," Parsons says. "Anytime they have something new and a lot of choice, or anytime they retire something, people show up," hoping to find another Beanie.

Even as she says this, a couple step to the counter with a half-dozen of them, including Quackers the duck and Hippity, Hoppity and Floppity - bunnies in three different pastel shades.

"Oh," Parsons says, "you're ready for Easter!"

"They're the first thing I look for, everywhere I go," notes Sharon, a visitor from Mobile, Ala., as her husband pays Parsons. "I just bought Curly in Park City. I was just on vacation in Florida and found a bunch of new ones. I have a nephew in Mississippi who looks for them for me."

She points to a misprint on the label of a few of her latest purchases. On the heart-shapped Ty tag it says "oriiginal" within the phrase "Beanie Original Baby."

"These could be valuable," says Sharon.

The Beanie Baby phenomenon, notes Anne Nickels, a Ty spokesman in Oakbrook, Ill., dates back to January 1994, when the first in the line were released.

"It started very slowly because it was all by word of mouth," she says, for the company does no national advertising at all. Children in the Chicago area, Ty Inc.'s home base, started collecting them in earnest in the summer of '95.

But sales really took off in January 1996, especially in the upper Midwest.

"My personal feeling is the kids in this area traveled over Christmas and either got them as gifts or saw something they liked," Nickels says. Most toys sell best in the weeks before the December holiday, but Beanie Babies seemed to counter that expectation.

The same sort of surge occurred in January 1996. "It was kind of odd, because they could be very, very popular in one town but in the next town they'd be no big deal," she says.

Then, last April, McDonalds began offering even smaller Beanie Babies - 10 Teenie Beanies - with Happy Meals for children. The promotion was supposed to last five or six weeks; the toys were gone in one, Nickels says.

"People bought the Happy Meals and threw them away to get the Teenie Babies," Rex notes. "They were `free'; now they're worth $10."

Today there are dozens of Web sites related to Beanie Babies (Ty's home page can be found at www.ty.com), as well as books, magazines and an album.

The toys' popularity swept the United States, and Beanie Babies are now making headway in Canada and Great Britain; Maple the bear is sold exclusively north of the border, and Brittania, also a bear, can be had only in England - much to collectors' consternation.

"I called two friends in England and had them checking for Brit-tania" after the toy came out, Rex says. "They said, `What is it with this Beanie Baby thing? Shops are getting 100-plus calls a day!' "

After making several contacts, Rex's friend called back with bad news. "I don't think you're going to get one," he told the Utahn.

Obviously, this is more than a hobby, collectors say: Beanie Babies seem to help people connect - officeworkers, shopkeepers and customers, Internet correspondents and families.

Sharon, the shopper from Alabama, says that besides buying them for herself, she purchases Beanies for her girls, both of whom have 75 of the soft toys.

"It's bonding," says Rex - "with those in the office, and with grandchildren" (he has 27). "My wife got us started."

"My grandkids know all of their names," says Anita, who works at a downtown law firm and often drops by Recollections to chat with Parsons. "They just come to my house and play with them."

The Salt Lake collectors have favorite merchants, from St. George to southern Idaho, including gift stores and, unique among local department stores, Nordstrom, which even has a Beanie Baby hotline.

"We ostracize some places," says Rex. "A few are way too mercenary."

A network of friends and acquaintances has grown up among those who collect the toys.

"If you hear of one being available, people start calling each other," Carolyn says.

"We say, `This is a BBA," adds Margaret - "a Beanie Baby alert!"

Indeed, Carolyn loves sharing the hobby with friends.

To a point.

Recently she bought several Valentinos, her favorite, intending to give the white bears to her girlfriends.

"And then I couldn't bring myself to do it."

The evidence is there on Carolyn's orderly spread sheets. Between Twigs the giraffe (she has three) and Velvet the black panther (two) is "Valentino the Bear with Heart."

She still has 15 of them.

*****

ADDITIONAL INFORMATION

10 Rare Beanie Babies

(and their estimated values in 1998)

- Spot (without spot) - Chilly

$1,500 $1,000

- Peanut (dark blue) - Nip (all gold)

$2,500 $750

- Quacker (no wings) - Humphrey

$1,500 $1,000

- Zip (all black) - Peking

$1,250 $1,000

- Patti (maroon) - Teddy Brown (old face)

$750 $1,000

Original price was $5-$7.

SOURCE: "The Beanie Baby Handbook"