"You're not listening," Fenrir said. "I hear you think its hopeless with the Death Eaters. Fine. All well and good then. I could certainly go threaten D'Eath, but vampires do not often become frightened by werewolves, just so you know. A bitter rivalry since before time itself. It has nothing to do with me. We're natural enemies by species. You know what I am, and he is half vampire. If you want to take that chance, then fine.
"If you want me to tell D'Eath you're through with the Death Eaters, I can relay the message. They've had defectors before, and they surely take Order defectors too, as you must well know. They might want conditions that you don't relay any sensitive Death Eater information, but if that's all they want, then that shouldn't be entirely impossible to negotiate.
"But, tell me, what exactly is it the Death Eaters want from you now? Sounds like they've pretty much thrown their best punch. If they've obliviated the memories of those you love--specifically your husband and children, then it makes it bloody worthless to kill you, if that's ultimately what they intend. A mammoth chunk of their bargaining power to keep you under their control is gone unless they want something yet. If it were simply about you keeping away from an Order do-gooder, then they've already accomplished what they wanted simply by obliviating them.
"Threatening your children is, at best, just blackmail. So, what is it you can do or what is it you know that is important to them?"