“That is the extraordinary part of it,” said Forbes, smiling grimly.  “People heard the noise, of course, but came to the conclusion that a cylinder in the car had back-fired.  That was the view taken by two policemen on duty within a few yards of the house.  A detective stationed in the cloakroom actually saw the man raising the weapon.  He, of course, was under no delusion as to what had happened, and ran out instantly, but the car was then traveling at a fast pace, and was out of sight before the nearest constable could even endeavor to stop it.  Anyhow, what was the man to do?  We cannot expect that he would whip out a revolver, if he carries one, and blaze away indiscriminately at car and occupants if the chauffeur refused to pull up.  Really, Theydon, Wong Li Fu has perplexed the authorities more than any desperado known to this generation.  He is aware that his hostage has escaped from Croydon, so he calmly drives past my house, knowing full well that it is efficiently guarded, and fires a pot shot at the first person seen through one of the windows.  The man whom I have spoken to over the telephone shares that opinion.  He is one of the legal advisers of the Home Office.  Just to show the baffling nature of the problem, he says that it will be absolutely impossible, on the evidence available at present, to frame a charge against any Chinaman other than Wong Li Fu.  Yet we know that he has at least four or five, and probably three times as many, accomplices.”

“Have the police yet obtained any real clew as to the whereabouts of the gang’s headquarters?  They must have some sort of meeting place.  They must eat and sleep somewhere.”

“That big detective, Winter, came here this morning.  He seemed to be very confident, though I think I gave him the worst shock he has received for many a year when I informed him that within an hour after he had left the house Mrs. Forbes had been shot at, and narrowly escaped a fatal wound.  It was he who asked me to invite you to come here.  I’m exceedingly sorry that our acquaintance, begun so happily, should involve you in personal risk—­”

“As for that,” broke in Theydon, “I would not change places with any man in England at this moment.”

He feared instantly that he might have said too much, and added with a laugh: 

“Don’t forget, Mr. Forbes, that I write books, some of them—­ the most popular ones, I am afraid—­ being of a sensational type.  When this tornado has died down, and Wong Li Fu is carefully hanged, and you and your family are recuperating in Sutherlandshire, I shall resume work with a new inspiration.  Never again shall I say to myself, ’Oh, that is too far-fetched,’ or fear that I am straining my readers’ credulity beyond bounds.  If a small gang of Chinamen and Japanese can hold up London, bamboozle the best men in Scotland Yard, and keep a man of your position a prisoner in his own house, I need have no fear of adopting any situation my fertile brain can evolve, because four days ago I would have scoffed at the things which have actually happened as quite impossible and therefore unbelievable.”