Thraxas and the Elvish Isles

In the fourth book of the Thraxas series, Thraxas is invited to the Elvish Island of Avula. Sailing south means he can avoid the harsh Turanian winter, and escape from Makri, who's recent behaviour has outraged all decent citizens. Makri refuses to be left behind, much to the displeasure of the Turanian Prince, who knows her Orcish blood isn't going to be welcome on any Elvish island. Once there, Thraxas finds himself involved in the puzzling case of the Elvish sacred tree, and Makri starts...