Mrs. McGillicuddy looked up at the rack where her various parcels reposed, with a pleased expression. The face towels had been excellent value and just what Margaret wanted, the space gun for Robby and the rabbit for Jean were highly satisfactory, and that evening coatee was just the thing she herself needed, warm but dressy. The pullover for Hector, too… her mind dwelt with approval on the soundness of her purchases.

Her satisfied gaze returned to the window, a train travelling in the opposite direction rushed by with a screech, making the windows rattle and causing her to start. The train clattered over points and passed through a station. Then it began suddenly to slow down, presumably in obedience to a signal.

For some minutes it crawled along, then stopped, presently it began to move forward again. Another up-train passed them, though with less vehemence than the first one. The train gathered speed again. At that moment another train, also on a downline, swerved inwards towards them, for a moment with almost alarming effect. For a time the two trains ran parallel, now one gaining a little, now the other. Mrs. McGillicuddy looked from her window through the windows of the parallel carriages. Most of the blinds were down, but occasionally the occupants of the carriages were visible. The other train was not very full and there were many empty carriages.

At the moment when the two trains gave the illusion of being stationary, a blind in one of the carriages flew up with a snap. Mrs. McGillicuddy looked into the lighted first-class carriage that was only a few feet away.

Then she drew her breath in with a gasp and half-rose to her feet. Standing with his back to the window and to her was a man. His hands were round the throat of a woman who faced him, and he was slowly, remorselessly, strangling her. Her eyes were starting from their sockets, her face was purple and congested. As Mrs. McGillicuddy watched, fascinated, the end came; the body went limp and crumpled in the man's hands.