In Neutral?

Recently, I've noticed that it's becomingly increasingly difficult to engage Roo in conversation. He's always been a quiet observer, but in his moments of quiet, he no longer seems to be observing, just absent. This absence concerns me, it seems to mark a new stage in the illness. Where does he go in these moments of absence? Is he sad, lonely, reflecting on life, dwelling on the next obsession? Or has his brain simply gone into neutral, as a friend suggested? I try to motivate him, when he's like this. I point out something on the radio, or start chatting about the kids. But he always goes back to that inner place. I hope there's some sort of peace there, because out here, it's disquieting and rather unnerving. Another loss, another adjustment.