Maniza Hussain knew that her younger son, the baby of the family, kept irregular hours, sometimes visiting the mosque in Stratford Street five times a day. At least twice a month he would announce he was going to stay with friends. When Maniza went out shopping, Hussain was still sleeping on the sofa. She never saw him again.

In the nearby Leeds suburb of Beeston, Hussain’s best friend, Shehzad Tanweer, was also preparing to leave behind the rundown brick terraces where he had spent all of his 22 years. A week earlier, he had hired a red Nissan Micra for the journey, using his own name and credit card. The car was already overdue to be returned to the car hire company. Tanweer didn’t care, for he had no intention of returning it.

The two friends were different in many ways. The younger boy, 6ft 2in, aggressive and argumentative, had always struggled at school. Gawky, ungainly and not very bright, he was overshadowed by his older brother, Imran, universally known as Immy, a glamorous figure in the tight-knit Asian community of south Leeds.

Hussain had got into trouble with the police for shoplifting, and left Matthew Murray Comprehensive with no GCSEs and one GNVQ in business studies. When he had started going to pubs, fighting and swearing, his worried parents had sent him to an Islamic study school in Pakistan, thinking that might give him more of a focus.

And it had. Religion seemed to have straightened him out, almost overnight. The scruffy, troubled boy who had left Leeds returned with an austere manner and an Islamic beard. He now wore the topi hat and flowing Islamic robes. Some of his contemporaries thought him “a bit of prat”, but his parents were relieved that he seemed to have settled down.

Shehzad Tanweer was cut from rather different cloth. A natural athlete with a good academic record, he had sailed through Wortley High School, and gone on to study sports science at Leeds Metropolitan University. His bedrooom was a shrine to sport, with a shelf full of trophies for the long-jump, football and cricket. Lean, sporty and self-assured, he helped out by running sports activities for children at the local social club, and worked part-time in his father’s fish and chip shop.

The Tanweers were comparatively well-off, and Shehzad considered himself rather stylish in his designer tracksuits and trainers. Even when wearing traditional Islamic garb to the mosque, he donned an adidas cap.

Like his younger friend, Tanweer had recently returned from an Islamic study school near Lahore. His religious fervour was fired by the experience, though he complained of the heat, the poverty and the attitude of the Pakistanis towards the British. Tanweer was proud of being British.

Only someone who knew them well would have noticed anything different about the two young men driving the Nissan. The day before leaving, Tanweer had dyed his hair and eyebrows light brown, in what may have been a rudimentary attempt at disguise. A week earlier, Hussain had shaved off his thick beard. It was now growing back. When a friend asked him why he had done this, his answer was peculiar: Hussain said he was sick of rival imams offering different rules on facial hair. “I don ’t like one mosque saying one thing, and one mosque saying another,” he had said, before adding portentously: “I will go my own way.”

At some point in the late afternoon or early evening, the friends linked up with the third member of the party, Mohammad Sidique Khan. At 30, Khan was the oldest of the trio, and in many ways the oddest: no naïve and angry youth, but a professional, married man, with a steady job, a pregnant wife, a baby daughter, a new council house, a season ticket to the gym and a silver Honda Civic. A thickset man with the big brown eyes of a spaniel, Khan was well known around Leeds. For five years he had worked as a learning mentor to children at Hillside Primary School, where about 30 per cent of the children have special needs. The children loved the big, soft-voiced man, and called him “buddy”.

Everyone agreed, Mohammad loved children; but not enough, apparently, to want to watch his own grow up.

Four years ago, he married Hasina Patel, an Indian Muslim three years his junior. In some ways, it was an unlikely pairing. Khan was a traditional Muslim, and growing more so, but his wife’s family was liberal. Hasina wore a burka, but they disagreed about the extremist Taleban regime in Afghanistan, of which Khan approved. There were rumours of a separation. A daughter, Maryam, was born 14 months ago, and Hasina told a neighbour she was pregnant again.

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