I turned it over in my mind.

“Yes,” I said, “it is morally justifiable so long as our object is to take no articles save those which are used for an illegal purpose.”

“Exactly.  Since it is morally justifiable, I have only to consider the question of personal risk.  Surely a gentleman should not lay much stress upon this, when a lady is in most desperate need of his help?”

“You will be in such a false position.”

“Well, that is part of the risk.  There is no other possible way of regaining these letters.  The unfortunate lady has not the money, and there are none of her people in whom she could confide.  To-morrow is the last day of grace, and unless we can get the letters to-night, this villain will be as good as his word and will bring about her ruin.  I must, therefore, abandon my client to her fate or I must play this last card.  Between ourselves, Watson, it’s a sporting duel between this fellow Milverton and me.  He had, as you saw, the best of the first exchanges, but my self-respect and my reputation are concerned to fight it to a finish.”

“Well, I don’t like it, but I suppose it must be,” said I.  “When do we start?”

“You are not coming.”

“Then you are not going,” said I.  “I give you my word of honour—­and I never broke it in my life—­that I will take a cab straight to the police-station and give you away, unless you let me share this adventure with you.”

“You can’t help me.”

“How do you know that?  You can’t tell what may happen.  Anyway, my resolution is taken.  Other people besides you have self-respect, and even reputations.”

Holmes had looked annoyed, but his brow cleared, and he clapped me on the shoulder.

“Well, well, my dear fellow, be it so.  We have shared this same room for some years, and it would be amusing if we ended by sharing the same cell.  You know, Watson, I don’t mind confessing to you that I have always had an idea that I would have made a highly efficient criminal.  This is the chance of my lifetime in that direction.  See here!” He took a neat little leather case out of a drawer, and opening it he exhibited a number of shining instruments.  “This is a first-class, up-to-date burgling kit, with nickel-plated jemmy, diamond-tipped glass-cutter, adaptable keys, and every modern improvement which the march of civilization demands.  Here, too, is my dark lantern.  Everything is in order.  Have you a pair of silent shoes?”

“I have rubber-soled tennis shoes.”

“Excellent!  And a mask?”

“I can make a couple out of black silk.”

“I can see that you have a strong, natural turn for this sort of thing.  Very good, do you make the masks.  We shall have some cold supper before we start.  It is now nine-thirty.  At eleven we shall drive as far as Church Row.  It is a quarter of an hour’s walk from there to Appledore Towers.  We shall be at work before midnight.  Milverton is a heavy sleeper, and retires punctually at ten-thirty.  With any luck we should be back here by two, with the Lady Eva’s letters in my pocket.”