The day I attended my interview for a job teaching at a challenging north London comprehensive school hadn’t begun in a particularly surprising way. I knew the score: prospective teachers are expected to take a lesson, then are given a tour of the school by student prefects and, finally, interviewed by the headteacher. It wasn’t until after I’d completed my morning teaching that things started to take an unconventional turn. Three boys turned up to show me around the school and took me first to the stairwell where students urinated because the toilets were broken and dangerous. Next, we walked through a waft of cannabis outside the sixth-form common room, before entering an aerial walkway connecting two buildings marked STRICTLY NO STUDENTS. One of the boys unlocked the door and we stood for a while, quietly looking out at a sweeping view of central London. Someone opened a packet of crisps. “I don’t get why you want to work in this fucking dump,” he said, offering me one. Moments later, I would learn that the “tour” I’d been given had been unofficial, to say the least. The boys ran off upon spotting the school’s deputy head, who exasperatedly asked where on earth I had been, and told me I was late for my job interview. It turned out that the students had skipped lessons to show me around without permission. Audacious, yes. But I was grateful: it was those students who showed me the school as they saw it, along with all of the challenges that they faced. To me, they were saying, “We have problems. Do you want to be a part of the team that will make a difference?” I decided I did. The school was tough, sometimes dangerous, but also full of creativity and joy. And I learned a lot, too. Speaking years later to a survivor of child criminal exploitation, who had excelled in my English class until his first prison sentence, for instance, I learned why he had felt connected to Shakespeare. He was 12 when he was groomed by a gang, hoping to escape poverty and domestic violence. Arrested for violent drug offences, he left class at 15, because his fear of punishment for a “drug debt”, a system of modern slavery, was stronger than my promises of a career. He was a vulnerable child, let down by failings in education, policing and social care. His ambition was to stay alive. For him, Romeo and Juliet was not hypothetical – it was personal. When Tybalt stabs Mercutio then “flies with his followers”, he could picture what that means; what real blood looks like on pavements, the ambulance arriving too late. Malorie Blackman’s Noughts & Crosses, a dystopian novel about a brutally racist society, resonated with students, perhaps because it hardly felt like fiction to boys for whom adultification and the assumption of criminality were a daily humiliation. One Saturday in the park, police accused one of my tutees of stealing his own bike, which he had outgrown. Taking my advice, he asked for their collar numbers so he could complain and retrieve his property. The officer said: “Don’t be so fucking cheeky.” The student was 12. Another boy was wearing his PE kit under his uniform to save time changing. Walking home, he was tackled to the ground by armed police who suspected the rucked material was a weapon. He was 11. The school was also full of wonder. A refugee child in my class progressed from analphabetic to English GCSE in 18 months. Many others had acquired fluency in multiple languages during their sometimes years-long odyssey to safety. And, besides accelerated learning, young refugees also have a talent for hope. A boy who had walked over 100 miles across a desert to escape a massacre later walked with my tutor group around Hampstead Heath to raise money for polar bears. Children thrive when their need for food and safety is met. What I loved most about being a teacher was taking students outside London where they could set down their carapace of street toughness to get muddy, hike up hills, rock climb, kayak and play. Last summer I joined Minority Matters, a north London charity, taking 50 young people to a remote farm in Wales for their first camping holiday. At 2am on the first night a commotion in the next tent woke me: two teenagers needed the toilet. “We’re scared,” the boys said, when I went to help. “There’s no street lights! What do we do?” I took them to the portable toilets across the field. On the way back we switched off our torches to see the stars. Their faces lit up. They were safer on a mountain farm in Wales than at home in their area of north London, with its record levels of deprivation, violent crime and drug gangs. They became children again: playing football on long grass, milking goats, herding sheep, spotting buzzards, cuddling kittens. No crime, no knives, no fear. Over the years many boys have told me they don’t expect to live beyond their teens. This is not an irrational fear. In June 2017, one of my loveliest students, Mahad Ali, a funny boy who was everyone’s friend, was stabbed to death. I dedicated 29 Locks, my novel celebrating London teenagers, to his memory. I will never forget the moment that changed me, standing on the forbidden walkway with my three guides, London at our feet and the smell of beef-flavoured crisps in the air. I owe them my career.