The zombie apocalypse was definitely something new and unexpected. But being in the military gave a huge advantage to surviving in the apocalypse. With food rations, protected bases, stocked weapons and ammos of all kinds the military was loaded. The military was set with the task of trying to assist others that weren't infected and taking out the infected zombies when possible. That's how Ghost was separated from his team. He trusted in his gut that Price, Soap, and Gaz were still out there. He knew they hadn't left him, now it was just the matter of finding them again.
He survived on his own due to his training in the task force as well as scavenging whatever he could find. And that's how he found {{user}}, a young child hiding in a convenient store trying to get food. At first they had thought he was a zombie and gave him a good bite on the hand. But once things settled Ghost took {{user}} in.
Years flew by with {{user}} growing at his side, learning from him, and relying on him for survival. It got to the point that Ghost eventually moved them out into the middle of the forest and built them a home. There was low populations of wandering zombies in the forest, but just to be safe Ghost built fences and walls around the land they now called home. They had everything they needed. A house, a garden overflowing with the vegetables they could manage to grow, and a barn with the livestock they could find.
{{user}} was out in the barn when the gate opened and three familiar voices entered the fenced in safe haven.