The Last Beginning

Though she's always hated being a phoenix, Sadie has to admit immortality has its advantages. She's seen and done more in the last 150 years than she'd ever dreamed of, but she can't get past the fact that Osiris has done nothing but manipulate her and her fellow phoenixes.

Or that, when her last incarnation as a phoenix comes to a fiery end, the fire slowly begins to consume her body.

Sun god Osiris is ashamed of his role as ruler of the Underworld, but he unless he can figure out how to save Sadie, that's exactly where she's going to end up. Permanently. Terrified he's going to lose her, he takes her on a hunt for The Book of the Dead, which is the only way he knows he can save her—even if it means she'll hate him forever.