This quest begins immediately after defeating the invaders of Naxos on the beach in the south west of the island. If you went on to do side quests at this point, you will find your mother still waiting on the beach. Speak with her to begin the quest. After questioning your mother, mount the nearby horse and ride with her to Naxos. Dismount when she does and speak with her again before heading to the construction of a nearby temple. After a series of cut scenes and some minor dialogue options the quest will complete.