“Grindelwald. And at last, my brother had an equal to talk to, someone just as bright and talented as he was. And looking after Ariana took a backseat then, while they were hatching all their plans for a new Wizarding order, and looking for Hallows, and whatever else it was they were so interested in. Grand plans for the benefit of all Wizardkind, and if one young girl got neglected, what did that matter, when Albus was working for the greater good?

Harry Potter and the Deathly Hollows - Chapter 28 : The Missing Mirror
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