"Symphony of Illumination" is the 12th episode of the seventh season of the CBS sitcom How I Met Your Mother, and the 148th episode overall. It aired on December 5, 2011. The episode is a continuation of the previous episode, "The Rebound Girl". It is the second most critically acclaimed episode of the 7th season (behind "Tick Tick Tick"), and has been well reviewed by critics, especially for its ending.