Chapter 61:

So Voldemort is a perfectionist seeking the "most powerful" combination of enemy, servant, and ancestor. Nice and good. But it sounds like if he were maybe a little less perfectionist, he could get any servant (I'm sure Lucius could spare Crabbe or Goyle, or he could just buy a house elf), any enemy (it's not like he doesn't have enough enemies, and anyone who wasn't an enemy before he took their blood would certainly be afterward), and so the only even slightly hard-to-come-by ingredient is the bones of the ancestor. So why in the name of Merlin haven't the bones of all Voldemort's ancestors been dug up and placed in a locked box under Dumbledore's desk? How come Mad-Eye Moody is out guarding the graveyard as if leaving Dark Lord Resurrection Ingredient #3 literally lying in the ground is at all safe?

(even so, an MoR-worthy solution would be for Voldemort to grab a sufficiently old hominid from a museum and assume it was common ancestor to everyone, but it would at least slow him down).