Although Miss C. mentioned it last week, I feel that we should devote some additional space to the recent Fifth Avenue apartment that made the New York Times last week.

The long and short of it is that a family paid to have their (fabulously expensive) apartment renovated. The family wanted something special, and boy is that what they got. During the renovation, architect/designer Eric Clough embarked on a multi-year secret project to hide puzzles in the apartment, unbeknownst to the apartment's owners, and not even discovered until months after the project's completion. The project included extensive historical research, puzzles, and even a soundtrack. Here's how it started:

What Ms. Sherry didn't realize until much later was that Mr. Clough had a number of other ideas about her apartment that he didn't share with her. It began when Mr. Klinsky threw in his two cents, a vague request that a poem he had written for and about his family be lodged in a wall somewhere, Ms. Sherry said, "put in a bottle and hidden away as if it were a time capsule." ... Before long, his firm, 212box, was knee-deep in code and cipher books, furnituremakers were devising secret compartments, and Mr. Clough's former colleague, Heather Bensko, an architectural and graphic designer who had been his best friend at the Yale School of Architecture, found herself researching the lives of 40 historical figures, starting with Francis I of France and ending with Mrs. Post.

Then things got weird, as the family's children began to notice themselves written into seemingly decorative elements within the apartment.

...one night four months later, Cavan Klinsky, who is now 11, had a friend over. The boy was lying on the floor in Cavan's bedroom, staring at dozens of letters that had been cut into the radiator grille. They seemed random — FDYDQ, for example. But all of a sudden the friend leapt up with a shriek, Ms. Sherry said, having realized that they were actually a cipher (a Caesar Shift cipher, to be precise), and that Cavan's name was the first word.

The family soon received a mysterious letter directing them to look deeper into the apartment, to discover its secrets. Through a series of eighteen clues, the family participated in an adventure in their own home, discovering the trail of secrets left for them by during the renovation. The scope and complexity of the puzzle is frankly mind-blowing:

...the finale involved, in part, removing decorative door knockers from two hallway panels, which fit together to make a crank, which in turn opened hidden panels in a credenza in the dining room, which displayed multiple keys and keyholes, which, when the correct ones were used, yielded drawers containing acrylic letters and a table-size cloth imprinted with the beginnings of a crossword puzzle, the answers to which led to one of the rectangular panels lining the tiny den, which concealed a chamfered magnetic cube, which could be used to open the 24 remaining panels, revealing, in large type, the poem written by Mr. Klinsky. (There is other stuff in there, too, but a more detailed explanation might drive a reader crazy.)

You owe it to yourself to take five minutes and read the full story. And if you have an $8.5 million apartment of your own just rusting away, why not hire Mr. Clough to add his personal touch?