In Chapter 22 theres a cut to two guards, Rash and Wrigga, talking about one of their first sightings of Kellhus' and Serwe's child. these two were setup to tell Cnaiir that the babys name was Moenghus, as soon as Cnaiir leaves, the two men look at each other
"then just to be certain. they resumed their fabricated conversation. As theyd been instructed."
Who set this up? Kellhus? To start the wheel rolling on Cnaiirs betrayal? Thats a odd way to inform Cnaiir that his son was born and named Moenghus. Natural word of mouth would of spread that info.