Eidos Interactive today announced an agreement with Microsoft for the release of two downloadable chapters in the continuing Tomb Raider adventures of Lara Croft. Containing up to six hours of new gameplay and content for Tomb Raider: Underworld, the chapters will be available exclusively on Xbox LIVE Marketplace for the Xbox 360. Tomb Raider: Underworld – Beneath the Ashes and Tomb Raider: Underworld – Lara’s Shadow will deliver two very different single player gameplay experiences. Tomb Raider: Underworld – Beneath the Ashes takes place after the Underworld story has finished and will feature an incredible new environment to explore, additional secrets to unlock and different enemies to fight. Tomb Raider: Underworld - Lara’s Shadow will introduce players to a new kind of playable character and create a unique Tomb Raider experience. A demo for Tomb Raider: Underworld will be available on Xbox LIVE Marketplace this month.