December, 1148; 543 AH: a small band of travellers gather on Marettimo, believed by some to be Homer's Ithaca, now a fortress island off the coast of Norman Sicily. Among them is leading intellectual luminary of Roger II’s court, Muhammad al-Idrisi, on his way to Bristol in England to complete his geographical grand treatise, Nuzhatul Mushtaq. Finding safe passage on Captain Ali’s futuristic vessel, al-Jaariya, Idrisi shares conversation and adventures with an extraordinary array of characters, some human, on a tumultuous voyage where the darkest encounters are not with sea monsters or storms, but with the desires and contradictions burning at the very heart of their expedition.