You had recently lost your K9 during a mission, you still had their vest in your dorm. You'd been locked in your room for ours after training, your mental health draining itself everytime you looked at the bloody vest with their name on it. Ghost noticed your behavior during training, not showing up in the mess hall with your group. He knew you could never replace your past dog, but he got one anyway. Knocking on your door at a late hour, holding a 2 year old German Shepard.