Maeglin returned to Gondolin saying nothing about his encounter with Morgoth, but many people noticed a change. Most thought it was for the better, though Idril suspected something and began work on Idril's Secret Way.
'And it came to pass that Eol saw Aredhel as she strayed among the tall trees near the borders of Nan Elmoth, a gleam of white in the dim land. Very fair she seemed to him, and he desired her; and he set his enchantments about her so that she could not find the ways out, but drew ever nearer to his dwelling in the depths of the wood.'
"The Elves were the first to charge. Their hatred for the goblins is cold and bitter. Their spears and swords shone in the gloom with a gleam of chill flame, so deadly was the wrath of the hands that held them." - The Hobbit ('The Clouds Burst,' Alan Lee)