The god of love may be blind, tradition has so decreed it, but the demon of jealousy has a hundred eyes, more keen than those of the lynx.
Anne Mie, pushed aside by Merlin's men when they forced their way into Deroulede's study, had, nevertheless, followed them to the door.

When the curtains were drawn aside and the room filled with light, she had seen Juliette enthroned, apparently calm and placid, upon the sofa.
It was instinct, the instinct born of her own rejected passion, which caused her to read in the beautiful girl's face all that lay hidden behind the pale, impassive mask.

That same second sight made her understand Merlin's hints and allusions.

She caught every inflection of his voice, heard everything, saw everything.
And in the midst of her anxiety and her terrors for the man she loved, there was the wild, primitive, intensely human joy at the thought of bringing that enthroned idol, who had stolen his love, down to earth at last.
Anne Mie was not clever; she was simple and childish, with no complexity of passions or devious ways of intellect.

It was her elemental jealousy which suggested the cunning plan for the unmasking of Juliette.