I had once more grasped the handle of the teapot when I made a rather curious discovery. At the bottom of the teacup lay a single lump of sugar. To the majority of persons it would have meant nothing. They would have assumed that they had dropped it in and forgotten it and would have proceeded to pour out the tea. But it happened that, at this time, I did not take sugar in my tea; whence it followed that the lump had not been put in by me. Assuming, therefore, that it had been carelessly dropped in by the waitress, I turned it out on the table, filled the cup, added the milk, and took a tentative draught to test the temperature.