But it was for his musical skill that the colonel had selected him for the piece of work on which he was now engaged. It was very elementary work for a man who could play the Waldstein sonata and read a score by Strauss; any school girl could have done it; but even the greatest philosopher has at times to perform the simple operation of washing his face, and the lieutenant need not have felt that he was demeaning himself by a task so much below his powers. For what Lieutenant Axel von Schwank was doing was simply to transcribe into musical notation, on a sheet of ruled music paper, the two lines of German with which the colonel had supplied him. Surely that is difficult, you say? He has only seven letters, A to G, to employ, representing the seven notes of the scale, and the German alphabet has twenty-six. What about the v’s, and w’s, and z’s in which the German language is so much superior to the French? But in the first place, remember that the German musician calls H the note which the less accomplished Englishman calls B, and in the second place that the range of most instruments, including the German flute, extends beyond a single octave. So that if the lieutenant writes this [Illustration: [musical note]] for A, there is nothing to prevent him writing [Illustration: [musical note]] for I, and by means of the sharps and flats he can even arrive at Z, without exceeding the compass of that dulcet instrument. He was busy with his transcription when he heard a scuffling of feet and the clank of swords in the opposite room. His fellow officers were hurrying to the street door. The colonel put his head in. "We are called to the trenches," he said. "Go on with that, and follow us when you have done." The lieutenant had sprung up, turned round and saluted. When his superior was gone, he sat down and set to work again. After all, he probably reflected, music has charms: it would preserve him for a few minutes more from the bullets of those hateful pigs the English. The house was in silence. A little while after the officers had departed, a strange, unshaven, unkempt face peered round the edge of the door, which the colonel had left open. It was a lined and somewhat careworn face; the eyes were bright and wild; the hair, very rough and tangled, was red. The face moved slowly forward; inch by inch a dirty, tattered khaki uniform showed itself; and the rays of the lamp on the table glinted on the blade of a long carving knife, held in the man’s right hand. He wore no boots, and his stockings made no sound as he tiptoed across the room. [Illustration: THE INTRUDER IN KHAKI]