Book: The Dark Below.
“They are all here, on Earth, I can feel them. His Eyes, who watch our worlds for him; the Hand whose grasp on Earth must be unbound; the Heart who ceases at nothing to bring Crota back. And Omnigul, his vile Will, the keeper of the worms, the mother of his spawn.
“Find them, defeat them all—as long as even one of these monsters walks the Earth, the threat of Crota will never fade.” - Eris Morn