What makes a great detective—at least in fiction?

Not long ago I had lunch with an acquaintance whose hobby is genealogy. He had recently broken through a brick wall (genealogy talk for dead end) through the use of DNA. Having solved his personal mystery he remarked that it would make a good book. I didn't contradict him but a good book, mystery or otherwise, generally requires an engaging, memorable character. The mystery is secondary, almost irrelevant.

Which is why The Lineup, edited by Otto Penzler, is such a valuable book for anyone who wants to write a mystery. The subtitle gives the game away: "The world's greatest crime writers tell the inside story of their greatest detectives." It's the inside story behind Harry Bosch, Jack Reacher, Precious Ramotswa, Inspector Morse, John Rebus, Spenser and fifteen more fictional sleuths.

Otto Penzler is the proprietor of The Mysterious Bookshop in New York City. Several years ago, attacked by big box stores like Barnes & Noble and Borders and the online retailer Amazon (this was before Amazon drove Boarders to the wall), the Bookshop was struggling. "Not being wealthy," he writes in the Introduction, "partially by accident of birth and the failure of my parents to leave me an obscene fortune, I was faced with the increasing difficulty of supporting a business that was bleeding money—some months a mere trickle, others a rushing, roaring hemorrhage. To illustrate the level of desperation to which I had fallen, I called for a staff meeting . . . "

For several years, Penzler had commissioned an original short Christmas mystery from one of the authors he knows. The store printed the stories in pamphlets and gave them to customers as a Christmas present to thank them for their patronage. What about commissioning authors a biography or profile of their series characters, produce only 100 copies of each in hardcover, and sell the autographed, limited-editions to those collectors who also buy a book or five?

"More than two years after initiating this series—" The Lineup was published in 2009. "—we're still in business, which, against all odds, has picked up nicely. Many clients come in, call, or write each month to ask who will write the next profile, and then buy books in order to get a copy."

The profiles vary as much as the original books. But the articles are fascinating. Here's Lee Child writing about the creation of his Jack Reacher series: "Character is king. There are probably fewer than six book every century remembered specifically for their plots. People remember characters. Same with television. Who remembers the Lone Ranger? Everybody. Who remembers any actual Lone Ranger story lines? Nobody. . . " Also. "If you can see a bandwagon, it's too late to get on. . . "

Here's Ian Rankin writing about the creation of John Rebus when he, Rankin, was a 24-year-old graduate literature student. He became fascinated by contemporary literary theory, "enjoying the 'game-playing' aspect of storytelling. Eventually I would name my own fictional detective after a type of picture-puzzle, and the mystery of his first adventure would be solved with the help of a professor of semiotics. That's the problem with Knots and Crosses (and one reason I find it hard to read the book these days)—it is so obviously written by a literature student . . . It seems to me now that I wasn't interested in Rebus as a person. He was a way of telling a story about Edinburgh, and of updating the doppelgänger tradition . . ."

Again: While The Lineup should be of interest to serious mystery readers if only for all the books cited in its pages, it is invaluable for anyone who aspires seriously to write a mystery.