Gideon said, “You can’t just control whether or not you’re carrying a necro.”
“Yes, you can,” said Harrow. “If you have the resources, and are willing to pay the price of using them.”
The hairs on the back of Gideon’s neck rose, wetly.
“Harrow,” she said slowly, “by resources, are you saying—”
“Two hundred children,” said Harrowhark tiredly. “From the ages of six weeks to eighteen years. They needed to all die more or less simultaneously, for it to work. My great-aunts measured out the organophosphates after weeks of mathematics. Our House pumped them through the cooling system.”
From somewhere beneath the pool, a filter made blurting sounds as it recycled the spilloff. Harrow said, “The infants alone generated enough thanergy to take out the entire planet. Babies always do—for some reason.”

Gideon the Ninth - Act Four, Chapter Thirty-One