The Synod is a college or a faction of magic based in the
country of Cyrodill. The Synod is one of the two major magical groups in Cyrodill ever since the fall of the Mages Guild at the start of the 4th era, the other being The College of whispers.
The only appearance the Synod makes in the game is in the quest, [[Skyrim:Revealing the Unseen|Revealing the Unseen]] for the [[Skyrim:College of Winterhold (faction)#Quests|College of Winterhold]]. In the quest you enter a dwarven ruin called [[Skyrim:Mzulft|Mzulft]]. Inside you meet a Synod member who is slowly dying, before he dies he informs you that the Synod made an expedition to Mzulft for a secret purpose. Throughout the ruins you see the corpses of other dead Synod members.
There is one living Synod member in the entire game, he meets you at the end of the ruin and desperately hopes you have a special crystal that his fellow comrades were trying to bring to him. Once you give him the crystal he shows you a special dwarven device that can harness the powers of the stars to create a map of Tamriel and all powerful artefacts in a particular region.
This particular Synod mage is slightly aggressive and paranoid, he has been waiting for the crystal for a long time in the ruins and has become slightly mentally unstable.