A prequel to the Wheel of Time books: how Moiraine met Lan, and the start of their quest to find the Dragon Reborn. I've just finished rereading the main WoT sequence, but I'd not bought this book before.
Unfortunately I think this is the weakest of the series by a long way; the very young Moiraine and Lan -- and several other characters -- we see here are so different from their later selves that this isn't really very illuminating with respect to the main story. There are some missed opportunities too: Elyas gets a namecheck but no more; Tam doesn't get mentioned. It's nice to get a bit more detail about how Aes Sedai are raised, but otherwise this is only for WoT completists; you aren't missing anything by skipping this one.