Driving along la Séptima, the main road into the centre of Bogotá, we find ourselves blocked by a high-speed convoy. Two Toyota Land Cruisers are shepherding a black Mercedes. One hugs its back bumper. The other sways beside it in the outside lane. Then we glimpse the roof of a third in front. The back door of the rear Toyota is wavering, as if it’s about to fly open. I can see a hand gripping the windowframe and I am expecting it to open the door and slam it properly shut. Until the door swings out on a bend and I see the neat black muzzle of a sub-machine gun. The hand pulls the door to, as a woman might slip a bra strap back under her dress, but holds it ajar, ready to fling it open the moment the Mercedes is blocked. I think of one of the children’s drawings Semana printed yesterday in an article on the psychological effects of the violence. Underneath the child had written: ‘We’re really afraid of the bodyguards. They’re so edgy and they leap out of their cars and fire without thinking of the school buses going past with children in.’

Eugenia, meanwhile, is curious to see who’s in the black Mercedes. She accelerates past the rear Toyota. This seems to me a little unwise but we’re running into traffic now and the convoy itself accelerates, dodging left and right, wherever there’s a gap, and swerving back into formation. The rear-gunner is ahead of us again, the back door veering open and the little black snake’s tongue of the gun barrel flickering in and out. But no one’s niftier than Eugenia in the hurtle and lurch of Bogotá traffic. As the convoy bears off to the right, she slips up on the inside. Someone we don’t recognize, a man in his sixties with a bald spot in thick brown hair, is leaning back on the cushions and talking to an elegant grey-haired woman beside him. With his right hand he is making a slow gesture, as if, in the course of a reflective Sunday afternoon drive, he were developing some subtle point.

There are no sodium lights in Bogotá. Street lighting is subdued and darkness presses down from the mountains, so thick you can almost rub it between your fingers.