Supermarket trauma tonight. I'd run out of just about everything so I went to the 24-hr Tesco in my break. For a start the traffic was horrendous. It's a) Friday night; b) a bank holiday weekend; c) during the Festival; and d) the Tattoo is still on. Every street was congested, not just with cars but with drunken clubbers, distracted theatre-goers, lost tourists. I managed to negotiate my way through it all and spent an agreeable 45 minutes mingling with the large crowd following a man with a pricing gun who was creating bargains. I think I got everything on my imaginary list, certainly got a lot of stuff that wasn't on it.

Then after moving through the checkout at a leisurely pace ("I only got an hour's sleep this morning! I don't know how I'm going to last the night," confided the assistant. "Ooo! Limes! What do you do with those?") I rejoined the traffic frenzy.

This time I had an added bonus: a silent migraine. I've had this before. I get a migraine aura -- nausea and weird visual effects -- but no headache. The visual effects are disconcerting, especially while driving. My field of vision is interrupted by a roughly circular jagged line of bright light, inside of which everything is blurred. In the bright, jagged part, I can't see. It's not a black spot or anything, it's just an absence of vision. Weird. It swallows up important visual clues like traffic lights, signs ... drunken pedestrians. The other bonus was that I met up with the post-Tattoo rush -- gajillions of pedestrians plus coaches, taxis, cars. A nightmare.

Obviously I survived. And the boot is full of lovely fruit and veg and meat. Treats: mint-flavoured Twix (I must have bought that just as the migraine thing was coming on, the thought of it makes me feel slightly sick now) and two extremely ripe, extremely cheap mangoes, yum.

I'm off home now. I've plotted a course that will avoid most of the central city turmoil. First I drive down to Berwick on Tweed, then cut across to Carlisle ...