He would wander the streets of occupied Mosul by day, chatting with shopkeepers and Islamic State fighters, visiting friends who worked at the hospital, swapping scraps of information.
He grew out his hair and his beard and wore the shortened trousers required by the extremists. He forced himself to witness the beheadings and stonings, so he could hear killers call out the names of the condemned and their supposed crimes.
By night, anonymously from his darkened room, Mosul Eye told the world what was happening. If caught, he too would be killed.
But after more than three years, his double life has grown too heavy to bear. He misses his name.
His secrets consume him, sap energy he'd rather use for his doctoral dissertation and for helping Mosul rebuild. In conversations with The Associated Press, he agonized over how to end the anonymity that plagues him. He made his decision. Mosul Eye is Omar Mohammed, historian, scholar, blogger. He is 31.
The revelation of his identity is for his thousands of readers and followers, for all his volunteers in Mosul who have been inspired by a man they have never seen. But above all, it is for the brother who died in the final battle and for his grieving mother.
"I can't be anonymous anymore. This is to say that I defeated ISIS. You can see me now, and you can know me now," he told The Associated Press.
Mohammed first posted about the Islamic State group under his own Facebook account, in the first few days after its fighters swept into Mosul, but a friend told him he risked being killed. So in those first days he made himself a promise: trust no one, document everything.
A newly minted teacher with a reputation for secular ideas, he had lost his university job.
He found another calling.
"My job as a historian requires an unbiased approach which I am going to adhere to and keep my personal opinion to myself," he wrote on that first day, June 18, 2014.
Mosul Eye became one of the outside world's main sources of news about the Islamic State fighters, their atrocities and their transformation of the city into a grotesque shadow of itself.
During Friday sermons, Mohammed feigned enthusiasm. He collected propaganda to post online later. He drank tea at the hospital, fishing for information.
Much of what he collected went on the blog. Other details he kept in his computer, for fear of giving away his identity. Someday, he promised, he would write history with them.
The most sensitive details initially came from two old friends: a doctor and a high school dropout who had joined an Islamic State intelligence unit.
Mohammed's information sometimes included photos of the fighters and commanders, complete with biographies surreptitiously pieced together during the course of his normal life that of an out-of-work scholar living at home.
"I used the two characters, the two personalities to serve each other," he said. He expanded into a Facebook page and a Twitter feed to parcel out information at a time when little news was escaping.
Intelligence agencies made contact as well and he rebuffed them.
"I am not a spy or a journalist," he would say. "I tell them this: If you want the information, it's published and it's public for free. Take it."
In March 2015, his catalog of horrors got to him.
"I was super ready to die," Mohammed said. "I was so tired of worrying about myself, my family, my brothers. I am not alive to worry, but I am alive to live this life. I thought: I am done.
(This story has not been edited by Business Standard staff and is auto-generated from a syndicated feed.)