“27 Carshalton Gardens,” said Tuppence, referring to the address.  “That’s Gloucester Road way.  Plenty of time to get there if we tube.”

“The following,” said Tommy, “is the plan of campaign.  It is my turn to assume the offensive.  Ushered into the presence of Mr. Carter, he and I wish each other good morning as is customary.  He then says:  ‘Please take a seat, Mr.—­er?’ To which I reply promptly and significantly:  ‘Edward Whittington!’ whereupon Mr. Carter turns purple in the face and gasps out:  ‘How much?’ Pocketing the usual fee of fifty pounds, I rejoin you in the road outside, and we proceed to the next address and repeat the performance.”

“Don’t be absurd, Tommy.  Now for the other letter.  Oh, this is from the Ritz!”

“A hundred pounds instead of fifty!”

“I’ll read it: 

“Dear sir,

“Re your advertisement, I should be glad if you would call round
somewhere about lunch-time. 
               “Yours truly,
               “Julius P. Hersheimmer.”

“Ha!” said Tommy.  “Do I smell a Boche?  Or only an American millionaire of unfortunate ancestry?  At all events we’ll call at lunch-time.  It’s a good time—­frequently leads to free food for two.”

Tuppence nodded assent.

“Now for Carter.  We’ll have to hurry.”

Carshalton Terrace proved to be an unimpeachable row of what Tuppence called “ladylike looking houses.”  They rang the bell at No. 27, and a neat maid answered the door.  She looked so respectable that Tuppence’s heart sank.  Upon Tommy’s request for Mr. Carter, she showed them into a small study on the ground floor where she left them.  Hardly a minute elapsed, however, before the door opened, and a tall man with a lean hawklike face and a tired manner entered the room.

“Mr. Y. A.?” he said, and smiled.  His smile was distinctly attractive.  “Do sit down, both of you.”

They obeyed.  He himself took a chair opposite to Tuppence and smiled at her encouragingly.  There was something in the quality of his smile that made the girl’s usual readiness desert her.

As he did not seem inclined to open the conversation, Tuppence was forced to begin.

“We wanted to know—­that is, would you be so kind as to tell us anything you know about Jane Finn?”

“Jane Finn?  Ah!” Mr. Carter appeared to reflect.  “Well, the question is, what do you know about her?”

Tuppence drew herself up.

“I don’t see that that’s got anything to do with it.”

“No?  But it has, you know, really it has.”  He smiled again in his tired way, and continued reflectively.  “So that brings us down to it again.  What do you know about Jane Finn?

“Come now,” he continued, as Tuppence remained silent.  “You must know something to have advertised as you did?” He leaned forward a little, his weary voice held a hint of persuasiveness.  “Suppose you tell me . . .”