Valkyrie screamed, sprinting toward Skulduggery. He looked up and reached out to her, but it was too late. f you've read the other Skulduggery books by Derek Landy (and you really should have read them by now), you've seen it all before: Some bad guy wants to bring about the end of the world, and Skulduggery and Valkyrie fight valiantly to stop it from happening. A few people get hurt, sure, but everything's all right in the end. Well, not this time.