Duel On Serrano was a lightsaber duel between Jedi Master Sifo-Dyas and former Jedi Master-now-Sith Lord Darth Tyranus. The duel takes place on the Serrano, the homeworld of Dooku, and occurs less than a month after the events of Sifo-Dyas's mission from Vohai and mission from Kamino. Although the circumstances of the lightsaber duel are unknown, (albeit except to Sidious, Dooku, and Sifo-Dyas), the outcome of the duel would result in Sifo-Dyas' death and Dooku's final descent and fall to the dark side of the Force, initially transforming Dooku into a full-fledged Sith Lord.