None of it should have happened but all of it did and the mounting coincidences and innocent errors fatally confused the initial search for Mary Beth McBride. And by the time that search evolved into anything like a proper investigation it was too late.

Mary was already a victim.

It began with something as ordinary as a puncture, which briefly caused a traffic jam on the rue du Chene along which the embassy driver, a local Belgian named Claude Luc, was taking a short cut to the school. The US security officer, William Boles, agreed that it was a bastard even as he was strictly following the well-rehearsed routine. Before allowing Luc to change the wheel he telephoned the embassy from the car phone for a back-up vehicle to collect Mary. And then he called the school to warn of the delay.

The confusion arose when the embassy duplicated that warning call: misunderstanding the second contact, the school secretary thought that the relief vehicle had already arrived and it was no longer necessary to keep the child on the premises.

The last of the stragglers were just being collected or driven away when Mary Beth McBride emerged on to the rue du Canal and realized there was no car waiting for her. Mary’s security briefing was as well rehearsed but far simpler than that of William Boles. She should have turned back into the building and asked someone to telephone the embassy to find out what had happened.

But Mary Beth McBride was a wilfully precocious, brace-toothed ten-year-old who welcomed the chance not only to prove she was quite capable of finding her own way, unescorted, around Brussels, but also to see her usual driver and escort, who she knew didn’t like her, take the blame during the later telling-off. It was they who would be punished, not she. No one ever punished her.