“We have to be found first,” Grim answered, and you could almost hear him smile.

“Quick then!  What do you want?” snapped Yussuf Dakmar.  Grim’s answer was the real surprise of the evening.  It bewildered me as much as it astonished Yussuf Dakmar.

“I want that letter that came from the Emir Feisul!”

“I haven’t got it!  I swear I haven’t!”

“I know that already, for I searched you.  Where is it?”

“Ask Allah!  It was stolen by a Sikh, who delivered it to someone in a house near the military hospital, who in turn gave it to an Arab, who brought it here.  I hoped that fellow Charkian might steal it back again, but you have spoiled everything.  Charkian will turn against me now to save himself.  What do you want with the letter?”

“I must have it!” Grim answered.  “The French agent—­”

“What—­Sidi Said?  You know him?”

“Surely.  He would pay me a thousand pounds for it.”

“May Allah change his face!  He only offered me five hundred!”

“You have seen him already, then?” Grim asked.  “I don’t believe you!  When did you see him?”

“On the way up here.  He stopped my cab to speak to me at the foot of the hill.”

I began to see the drift of Grim’s purpose.  He had established the fact that the French secret agent was already on the track of the letter, and that in turn explained why he had not seized Yussuf Dakmar and put him in jail.  It was better to use the man, as the sequel proved.  And Yussuf Dakmar walked straight into Grim’s trap.

“What is your name?” he demanded.

“Call me Omar,” said Grim.

“A Turk, are you?  Well, Omar, let us help each other to get that letter, and divide the reward.  Sidi Said told me that the British are sure to confront Feisul with it, and to do it secretly if they can.  They will try to send it to Damascus.  Let us two find out who takes it, and waylay him.”

“Why should I divide with you?” demanded Grim, who is much too good an actor to pretend to agree without bargaining.

“Because otherwise you will not succeed.  I was afraid of you when you first surprised me with Charkian.  But now that I know you for a spy in the pay of the French I am not afraid of you, even though you have my revolver and dagger.  You dare not kill me, for I would shout for help and the guard would come.  You are in danger as much as I am.  So you may either agree to work with me, sharing the reward, or you may work alone and have nothing for your pains; for I shall bring accomplices to help me take the letter from you after you have stolen it!”

Well, I suppose that anyone with criminal intentions could submit gracefully to that much blackmail.  Besides, Grim was rather pressed for time and couldn’t afford to prolong the argument.

“I see you are a determined man,” he answered.  “Your demand is unreasonable, but I must agree to it.”