The good news is that the Gold Quartet has been invited to play one of their favorite concertos as guest artists with the noted Berlin Philharmonic. The bad news? The concert falls on Ruby's birthday, so she'll be traveling to Europe with her fellow musicians instead of celebrating at home with family and friends. The guys hatch a plan to make it up to her, a plan to celebrate Ruby's birthday in a way she'll never forget. Playing with one of the foremost orchestras in the world is cool, but fulfilling one of Ruby's naughtiest fantasies is even better. Her three trusted friends and lovers take her on a ride of deep, passionate surrender, bringing this quartet of sensual stories to a spectacular close.