Before the outbreak, Nicholas William Brooks was an aide to a the UN Ambassador of the United States.
He went to law school at Stanford where he obtained his Master's in Philosophy. He was an avid activist and during one of his protests he managed to get recruited to help in Obama's campaign for change in 2007. After working for some time he eventually found himself working under the wing of a woman named Rosemary DiCarlo (United Nations Ambassador for the US in 2013). After she retired, he worked underneath Samantha Power, a woman with whom he worked with before during Obama's campaign in 2007. She kept him on for his intellect and advice, and they eventually became close friends, and she wanted his help to smooth over the Russian/Chanarossian conflict.
During his time in Novigrad, he was in fierce negotiations for time and peace, but his words only fell on deaf ears.
When the incident occurred and the UN peacemakers were being evacuated, he did not make it to the transports to Miroslavl like he was supposed to because his wife had fallen ill, and he sent her in his stead when the boats were out of room and accepting only UN personnel. He tricked the officer in charge of the evacuation into believing she was the UN peacekeeper, while he stayed and would wait for the promised civilian transports. Only those transports never came. Forced to stay in Electrovadsk for the worst of it, he found himself in the unlikely situation of having to bear arms and fight for his life alongside the US Marines stationed there. When they started making their retreat, he'd almost gone with them, until he learned their destination was not Miroslavl, where his wife was. Instead he stays behind and attempts to venture southward on foot.
When he hears news of Miroslavl being attacked by infected, he makes it his goal to get there as soon as possible. Until, seconds later, he sees in the same news footage of his wife... ripping into the flesh of those UN peacekeepers and medical researchers with her hands and teeth. The picture is unmistakably her.