Harry Potter and the Deathly Hallows
How we cite our quotes:
Harry met her eyes with a mixture of defiance and shame. He remembered the words that had been engraved over the gateway to Nurmengard: FOR THE GREATER GOOD. He pushed the idea away. What choice did they have? (25.38)
Perseverance isn't always a good thing. Here, Harry struggles with his conscience, and with Hermione, over how to sneakily slip out of his agreement to give Griphook the sword of Gryffindor. He forces himself to believe it's the only option, against his gut feeling.
What if, what if, the boy knew about the others? Could he know, had he already acted, had he traced more of them? Was Dumbledore at the root of this? Dumbledore, who had always suspected him, Dumbledore, dead on his orders; Dumbledore, whose wand was his now, yet who reached out from the ignominy of death through the boy, the boy –. (27.30)
Voldemort is frustrated and confused by one of Dumbledore's most amazing qualities – his seeming determination, even from beyond the grave. The idea that his old enemy could somehow have planted the seeds of some plan in Harry frightens and angers the Dark Lord.
"We're his army," said Neville. "Dumbledore's Army. We were all in it together, we've been keeping it going while you three have been off on your own –."
"It hasn't exactly been a picnic, mate," said Ron.
"I never said it had, but I don't see why you don't trust us. Everyone in this room's been fighting and they've been driven in here because the Carrows were hunting them down. Everyone in here's proven they're loyal to Dumbledore – loyal to you." (29.34)
Faithful Neville stands up to Harry a bit here, reminding him that he's not alone – everyone in the DA has proven their mettle, and they've just been holding down the fort until Harry returned.