Kuje, a medium-security facility, is the testbed of Nigeria’s prison-based countering violent extremism (CVE) programme, launched in March. At its heart is the idea of “treating” the men on terrorism-related charges: that through activities like therapy, sport, schooling and vocational training, their behaviour can be modified; the risk of them recruiting while inside reduced; and eventually they can be reintegrated into society.

Building a bond between the “treatment team” and the Boko Haram inmates, officially known as “clients”, is seen as crucial to the success of the CVE strategy. Tata talks in patriotic terms about why he joined the team, and his belief that in doing God’s work, he earns a spiritual reward.

That offers some comfort. “These are very, very dangerous people. Anything can happen. We know they communicate with their people on the outside,” he reminds me.

Tata has personal experience of the risks: he was wounded during an attack on a prison by Boko Haram, although he refuses to talk about it. He believes the military tide has turned and now the insurgents are on the run. The “clients” in Kuje “know they are losing,” he says. “They watch TV.”

The day I visit the prison, Arsenal is playing Chelsea in Kuje’s version of the Champions League: both prison teams lustily supported, the cheers floating over the yard wall.

But my destination is the “de-rad” wing, a quieter, more secluded set of modern classrooms, originally planned as an open university. Unlike the rest of the austere prison, there is even air-conditioning.

I sit down in a small room with one of the “clients”. The stocky man on the other side of the desk wears jeans and a tight t-shirt. He has an Afro, a scraggly beard and a large ring on his finger. He calls himself a commander, but looks more like a guy you might see in a club. He speaks in Hausa, the lingua franca of the north, in short sentences, finishing each thought with a “tell him” to the imam who is translating – eager for his story to be understood.

Halfway through the interview, the “commander,” who doesn’t want to reveal his name, pauses. The imam has a cold so he leans forward and asks whether he wants the air-conditioning turned off. It seems a genuine, solicitous moment.

He sees himself as a transformed man, which he ascribes to Tata and his team. When asked during the interview where the Qur’an justifies killing civilians, the commander repeatedly says he can’t remember. It becomes clear that he doesn’t want to explore that old frame of mind. “I’ve changed. I don’t want to talk about justification.” The imam suggests we move on.