I dream that Winston Churchill is in my kitchen, methodically wiping my worktops and wondering, in his windy way, what is to be done about al-Qa'ida. When I wake, Conor is asking more or less the same question. "But if they know who the baddies are, why don't they put them in jail?" he asks, shovelling in the Weetabix with Winnie-like gusto.
"Well, " I explain, "They may know who the bombers are but they don't know where they are."
"Ah," says Con, rubbing his chin. "They need a Spy Tracker system." Our own tracking system has been in place for some days now. An inspired birthday gift from Con's godparents, it is a complicated arrangement of battery-operated sensors which tells Spymaster Con exactly where in the house each member of the family is at any time. His greatest intelligence coup so far has been to record the number of times I visit the lavatory in an evening . I'm not sure the system can be stretched to apprehend terrorists on five continents but I assure Con that something of the sort (and, I privately consider, of much the same efficacy) will already be in place.
Clara, meanwhile, is curious about the morning's headlines about the Madrid atrocity. "What do they mean - 'Could it be us next?', she wants to know. "Why in the world would anyone want to bomb us?" I haven't the stomach - or the time - to explain the principles (what principles?) of international terrorism to an eight-year-old and a six-year-old over breakfast, but Con has the situation taped. "Because," he explains, morphing before his distressed mother's eyes from Churchill to George W Bush, "they are the baddies and we are the goodies."
Later in the morning, I have to take Clara and a little friend across town to a ballet exam. The decision to take the underground or overground train is, today, charged with dread. I grew up with bomb scares. At school in Ulster in the mid-Seventies, every exam period saw a dramatic rise in hoax calls, which sent us whooping into the playground where teachers crossly counted heads and issued dire threats against time-wasters. All the rhetoric about carrying on as normal and not "giving in" to terrorists comes back with almost religious force, like a litany internalised in childhood. But it's different when you're the grown-up, when you're the one making utterly spurious decisions for your family's safety. As the Tube rumbles through King's Cross and Victoria, I don't think I'm imagining the tension as the awful footage from Atocha and El Pozo replays in every passenger's head.
"Just stand by the doors, girls," I say, as if it could possibly make a difference where we position ourselves in an almost empty carriage. "We're getting off soon."
Clara's nerves are all ballet-related and she and her friend witter companionably about the fears for the exam ahead.
I give each of them a hug and tell them there's nothing to be frightened of. I tell myself the same thing. But motherhood makes cowards of us all.