“Good God!” cried Aubrey.  “Did he get it?”

This emphasis brought no surprise to the bookseller, who was accustomed to the oddities of edition hunters.

“No,” he said.  “We didn’t have a copy.  We haven’t seen one for a long time.”

“Was he a little bald man with a red beard and bright blue eyes?” asked Aubrey hoarsely.

“Yes—­Mr. Mifflin of Brooklyn.  Do you know him?”

“I should say I do!” cried Aubrey.  “Where has he gone? 
I’ve been hunting him all over town, the scoundrel!”

The bookseller, douce man, had seen too many eccentric customers to be shocked by the vehemence of his questioner.

“He was here a moment ago,” he said gently, and gazed with a mild interest upon the excited young advertising man.  “I daresay you’ll find him just outside, in Ludlow Street.”

“Where’s that?”

The tall man—­and I don’t see why I should scruple to name him, for it was Philip Warner—­explained that Ludlow Street was the narrow alley that runs along one side of Leary’s and elbows at right angles behind the shop.  Down the flank of the store, along this narrow little street, run shelves of books under a penthouse.  It is here that Leary’s displays its stock of ragamuffin ten-centers—­ queer dingy volumes that call to the hearts of gentle questers.  Along these historic shelves many troubled spirits have come as near happiness as they are like to get . . . for after all, happiness (as the mathematicians might say) lies on a curve, and we approach it only by asymptote. . . .  The frequenters of this alley call themselves whimsically The Ludlow Street Business Men’s Association, and Charles Lamb or Eugene Field would have been proud to preside at their annual dinners, at which the members recount their happiest book-finds of the year.

Aubrey rushed out of the shop and looked down the alley.  Half a dozen Ludlow Street Business Men were groping among the shelves.  Then, down at the far end, his small face poked into an open volume, he saw Roger.  He approached with a rapid stride.

“Well,” he said angrily, “here you are!”

Roger looked up from his book good-humouredly.  Apparently, in the zeal of his favourite pastime, he had forgotten where he was.

“Hullo!” he said.  “What are you doing in Brooklyn?  Look here, here’s a copy of Tooke’s Pantheon——­”

“What’s the idea?” cried Aubrey harshly.  “Are you trying to kid me?  What are you and Weintraub framing up here in Philadelphia?”

Roger’s mind came back to Ludlow Street.  He looked with some surprise at the flushed face of the young man, and put the book back in its place on the shelf, making a mental note of its location.  His disappointment of the morning came back to him with some irritation.

“What are you talking about?” he said.  “What the deuce business is it of yours?”

“I’ll make it my business,” said Aubrey, and shook his fist in the bookseller’s face.  “I’ve been trailing you, you scoundrel, and I want to know what kind of a game you’re playing.”