I never got into the Dark Tower series although some have told me it's his masterpiece. I know it's supposed to link to a lot of his other works, including The Talisman, The Stand, Salem's Lot and so on. One of these days I'll have to give it a shot.

"When the snows fall and the white winds blow, the lone wolf dies but the pack survives."
Winter is Coming

Now this is the Law of the Jungle—as old and as true as the sky; And the wolf that shall keep it may prosper, but the wolf that shall break it must die.
As the creeper that girdles the tree-trunk, the Law runneth forward and back; For the strength of the Pack is the Wolf, and the strength of the Wolf is the Pack.