The road was now not so crowded as it had been. Minutes would pass and only a few travellers would come, and minutes more would go when nobody was in sight at all.
Then two men came down the road: they were clerics.
"I never saw that kind of uniform before," said mac an Da'v.
"Even if you didn't," said Mongan, "there are plenty of them about. They are men that don't believe in our gods," said he.
"Do they not, indeed?" said mac an Da'v. "The rascals!" said he. "What, what would Mananna'n say to that?"
"The one in front carrying the big book is Tibraide'. He is the priest of Cell Camain, and he is the chief of those two."
"Indeed, and indeed!" said mac an Da'v. "The one behind must be his servant, for he has a load on his back."
The priests were reading their offices, and mac an Da'v marvelled at that.
"What is it they are doing?" said he.
"They are reading."
"Indeed, and indeed they are," said mac an Da'v. "I can't make out a word of the language except that the man behind says amen, amen, every time the man in front puts a grunt out of him. And they don't like our gods at all!" said mac an Da'v.
"They do not," said Mongan.
"Play a trick on them, master," said mac an Da'v. Mongan agreed to play a trick on the priests.
He looked at them hard for a minute, and then he waved his hand at them.
The two priests stopped, and they stared straight in front of them, and then they looked at each other, and then they looked at the sky. The clerk began to bless himself, and then Tibraide' began to bless himself, and after that they didn't know what to do. For where there had been a road with hedges on each side and fields stretching beyond them, there was now no road, no hedge, no field; but there was a great broad river sweeping across their path; a mighty tumble of yellowy-brown waters, very swift, very savage; churning and billowing and jockeying among rough boulders and islands of stone. It was a water of villainous depth and of detestable wetness; of ugly hurrying and of desolate cavernous sound. At a little to their right there was a thin uncomely bridge that waggled across the torrent.
Tibraide' rubbed his eyes, and then he looked again. "Do you see what I see?" said he to the clerk.
"I don't know what you see," said the clerk, "but what I see I never did see before, and I wish I did not see it now."
"I was born in this place," said Tibraide', "my father was born here before me, and my grandfather was born here before him, but until this day and this minute I never saw a river here before, and I never heard of one."
"What will we do at all?" said the clerk. "What will we do at all?"
"We will be sensible," said Tibraide' sternly, "and we will go about our business," said he. "If rivers fall out of the sky what has that to do with you, and if there is a river here, which there is, why, thank God, there is a bridge over it too."
"Would you put a toe on that bridge?" said the clerk. "What is the bridge for?" said Tibraide' Mongan and mac an Da'v followed them.
When they got to the middle of the bridge it broke under them, and they were precipitated into that boiling yellow flood.
Mongan snatched at the book as it fell from Tibraide''s hand.
"Won't you let them drown, master?" asked mac an Da'v.
"No," said Mongan, "I'll send them a mile down the stream, and then they can come to land."
Mongan then took on himself the form of Tibraide' and he turned mac an Da'v into the shape of the clerk.
"My head has gone bald," said the servant in a whisper.
"That is part of it," replied Mongan. "So long as we know?' said mac an Da'v.
They went on then to meet the King of Leinster.