Whilst Arthur was moving from Carohaise to London, Merlin crossed the Channel into the Armorican peninsula. His purpose was to implore the principal kings and crowned dukes of Brittany to join their lord on Salisbury Plain where the Christian army was due to assemble.
At the time when this story took place, Merlin had just turned thirty. He was tall, handsome, courteous but audacious, with a remarkably good temper. Because of the aura of the prestige of his gifts, he would not have lacked for feminine company had not the fear of losing the friendship of God induced him to mistrust women. Thus it was that so far he had kept himself free from any carnal sin. However, a mere slip of a girl, almost a child, was to be the occasion of his downfall.
Whilst journeying by horse in Brittany it was quite by chance that Merlin found himself on the edge of the Forest of Broceliande. . He did not have the strength of heart to alter course. However he, who knew everything, knew that there he would meet Viviane - Viviane, she, who would lose him, if he committed the folly of falling in love with her ; but knowledge of the future is never an invitation to prudence... Yet, on that day, his heart overruled his head. The desire to know his real enemy had been worrying him for a long time. Now he was offered the chance of confrontation. What was the risk in it ? Forewarned against Viviane, as he was, how could he lose his head ?... His curiosity once satisfied, doubtless he would recover his peace of mind.
So it was that Merlin struggled to justify himself in his own eyes even before succumbing.
The Valley without Return was quite close. The manor of Dyonas, Viviane's father, lay tucked away at the end of it ; but the young girl was hardly ever there, preferring the company of her own dreams to that of anybody else.
From this valley led a track, almost a footpath , which the inhabitants of the forest , almost shaking with fear, used to call the "Path of Mad Thoughts" ; and not without reason, the clear spring which watered it was held to be enchanted.
Besides, the name of this spring has not changed: to this day it is still called the Fountain of Barenton. Even though the great trees, full of birds of all kinds, which originally enclosed the valley have disappeared, it continues to cast its spell.
Overwhelmed by her desire to be alone, Viviane could not have wished for a more welcoming or sechuded retreat. She went there often when her father was away.
Knowing that the girl would be at Barenton that day, Merlin took care to let his horse follow a path which led directly to her. A joyful haste drew him towards his destiny: regret would only follow later.