Ok so hi everyone- *Me who has never made a theory before* .... Line? Anyways, Enough with the small talk, lets get to the theory. So anyways- When fox was saying something about the crystal grave and that shadow killed someone, Crystal got mad and is probably leaving the pack soon. But... Who does crystal think shadow killed? Well, I think its ruby. Here is some evidence: So first of all, Ruby hasn't been in ANY of the chapters of fate even though she is crystal's sister. Second of all, I assume the crystal grave is where royal dead wolves are buried, Since many of the royals are named after crystals (Lapis, Crystal, Ruby, Agate, Etc) And since Crystal was very upset about it, Who else could be the victim of who Crystal believes to be Shadow? Now now, I know what your thinking. It could have been her mom or her dad, sure, But lets be honest, Her parents don't have as much as an important role in Crystals as Ruby does. (And side note, Ruby's pups aren't in Fate so that might also be a tiny bit of evidence, but idk if its important or not)
Edit: I re-read fate and ruby is alive screw this theory XD