"Then we mix it with rat poison," Yelena replies grimly.

One corner of her mouth twitches slightly upwards at the warning, and she lifts the hand holding her knife slightly, to show it angled along her arm, the better to turn away any horrible, questing mouths without risking the sort of prolonged contact that might allow them to contaminate her.

"I know to be careful. But I promise I will not be mad if one of them gets its teeth into me, and you have to hit me to make it let go."

Better that than those teeth digging into her mind, making her want to feed and shelter them. Far, far better.