Knowledge Arcana Check

Okay, this is my fault. Knowledge Arcana checks can be made to figure things out about constructs, which includes living constructs. When Tim's PCs first met Loner, the warforged barbarian with the Greataxe that was running around the tunnels still fighting the last war, they needed the gnome journalist to fill them in. (Which is one of the reasons that I had him accompany them, especially since Tim was not used to the Eberron Campaign Setting.)

However, in a post from last week, the PCs found the secret door to the middle of the vat, and opened it, noticing that Loner's body was missing. By this point Castille had ranks in Knowledge Arcana and I should have asked for a check. I forgot. (Whoops.)

So, Knowledge Arcana check please.