The Riddle is absolutely fantabulous. I won't give much away, but i'll tell you this, i couldn't put it down (even though i new i was supposed to be doing A'level revision - opps :-)).
After discovering the Gift at my school library i was hooked on Alison Croggans world and characters. In the riddle Maerad and Cadvan set out looking for the Treesong - this search takes them north. Its a hard journey - scraps with both the dark and the light - the latter has a profound effect on Maerad and Cadvans relationship. But there are some pretty hilarious scenes - namely to do with a lion and rabbit (read and find out) lol.
Certainly a must read!