So, he was neither in a coma nor otherwise dreaming. He has not died and then come back to life. Nothing catastrophic has happened to him that would explain the darkness into which he awoke. There is nothing obvious that would explain the hallucinatory existence he has just experienced -- the business with The Magnificence, the priests who turned into a monster and hacked his hand off, The Committee that elected him as chair and then charged him to execute someone -- and that whole bit about delving into the individual and collected inner being of the other members of The Committee.
Now, he is here. He has woken up in a boat after deciding to execute himself as a member of The Committee. This was a violent transition of the sort he thinks he should have undergone in order to have gone into that other strange world. He cannot understand, cannot convince himself, that that other world is not to be separated from this world. There has been no transition. This is what Ro is telling him. And yet, two questions persist:
1: What brought him to the darkness?
2: If there is no transition, what happened to him between his shooting himself in the head and his waking in the boat, floating in the Chesapeake Bay?