Even Nathan, who is the last Cain, after all, has no access to this information.
The question is, what now? These new people came into my life and they expect me to tell them what to do next, to help them carry on the mission. How do I do this when I can't even control my magic as it keeps bursting out of me?
It's clear now that Nathan and I are tied to each other. I need him to teach me how to control my powers, and he needs me to unlock the mausoleum. Only together can we fulfill this mission.
But I wonder if that's the only reason that keeps him here, with me.