They call it Blue Monday, the mid-January Monday said to be the most depressing date on the northern hemisphere calendar. To raise the spirits, I prescribed myself a walk. It was the kind of weather for which the word dreich might have been invented. A cold mizzle hung over the world. Low cloud guarded the horizon. A thin wind cut. The only thing moving was the flock of black-headed gulls ghosting by overhead; even in the soupy murk they seemed to know where they were going. Nothing else stirred.