The Challenge Series Expansion is a free downloadable content pack for Need for Speed: Undercover that was made available for PlayStation 3 on April 30, 2009, for PC through patch 1.0.1.18 on May 6, 2009, and for Xbox 360 on May 28, 2009. Upon downloading the expansion and completing the prologue police pursuit in career mode, the challenge series can be accessed through the pause menu.