CHICAGO -- If this story were a crime thriller, detectives would find David Adler's fingerprints all over decorator Athalie Derse's home in the North Shore of Chicago. The place is clearly the handiwork of the great 1920s country-house architect, though Adler might find its current location a bit puzzling.

It seems that back in 1953 a Chicago newspaper's art director convinced the owners of a magnificent 1923 Adler-designed estate, a pale-brick French chateau inspired by the pavillon de La Lanterne at Versailles, to sell him the north wing of their house. The gentleman then proceeded to have his new purchase amputated from the main structure, hoisted onto rails and trundled about 100 yards across the lawn. There the former wing sits today, gazing back at the distant silhouette of its old address. It's a pre-preservation-era tale that has long brought tears to the eyes of Adler fanatics; that is until Athalie (everyone calls her Missy) Derse came along.

"When I heard it was for sale I just had to see it, even though I wasn't thinking of moving," says Derse, a lifelong Adler admirer, recalling the day in 2001 she called her real estate agent to ask for just a little peek at that wandering wing. "Lo and behold, I fell completely in love and that was the end of that," she says with a laugh.

As the owner of the Lake Forest design firm Athalie Derse Inc., Derse is no stranger to historical renovation. She is currently working on an Adler-designed house owned by Billy Corgan of the Smashing Pumpkins (apparently even rock stars love Adler - who knew?).

But even with all her experience, the orphaned wing was an overwhelming project. The previous owners had decamped for New York in the middle of a gut rehab of the house, and Derse was forced to undertake more than a year of painstaking reconstruction. Every decision she made was grounded in her heroic notions of Adler, who died in 1949, as architectural oracle.

Reclaiming the place's artistic soul meant being crazy strict on details, like copying the library's Adler-designed French casement windows and hardware right down to the brass screws. Other Adler details are everywhere, like the statuesque ebony doors that flank the dining room (also copied from the main house) and a romantic little spiral staircase with a fairy-tale perfect plaster surround that leads up to the master bedroom.

"It feels like being in a treehouse up there," says Derse of the master suite. It was originally a guest room in the pre-amputation days, and its new master bath is one of the house's true jewels. Inspired by photos of a mirrored dressing room that Adler designed in 1931 for the home of meatpacking baron Lester Armour (interiors of that Adler house can be seen in the Robert Altman film, "A Wedding"), Derse made the bath a glamorous Garbo-esque mirrored boudoir.

With the grueling rehab over, filling the luminous rooms was a cinch by comparison, and Derse knew the images she wanted to evoke. The dining room is her "ice palace." "I wanted the lightest shade of gray walls to make the room very austere," she says. "The dark furniture and the black and white floor provide all the visual activity I need." In the living room she wanted "a completely different scene, a nighttime room."

Despite Derse's confessed Adler worship, the finished project is not some acolyte's shrine but a real family home. Her two skittish Scotties and loopy golden retriever have the run of the place, as do her teenagers and their friends, and, with the appropriate oversight, she says, even her husband.