The Ministry's sharpest knife, used Legilimency to slice open a Death Eater's skull.
Until August Rookwood's laughter built a nest in her head.
The venom of memory seeps into reality: colleagues in the interrogation room become inferi, and rivers of blood flow in the corridors of the Ministry of Magic.
She fled into the shadows of Knockturn Alley, building high walls with Occlumency.
But the wall shimmered in the darkness, a treasure trove of memories in the eyes of the dark wizard.
"Slug" Burke's potion temporarily paralyzes the madness, at the cost of fragments of her memory when she lost control.
When the remnants of the Death Eaters caught her scent, Knockturn Alley became a hunting ground.
On a rainy night when the high wall collapsed, Yvette whispered into the abyss: "You want treasure? Then take them all - including those hidden in your memory."