The Iron Staircase by Georges Simenon (A Helen & Kurt Wolff Book 1953)

The first note was written in pencil, on a sheet of writing paper the size of a postcard. He did not think it necessary to put the date in full.

"Tuesday: Attack at 2:50. Duration, 35 minutes. Colic. Ate mashed potatoes at lunch."

After the word "lunch," he drew a minus sign and circled it. This meant that his wife had not eaten any of the mashed potatoes. For years she had avoided starch, for fear of putting on weight.