race continues, several of the vessels are destroyed by explosions. The Doctor suspects that the crew aboard the Buccaneer, which is a 17th-century pirate ship, is responsible, as it was the closest vessel at the time of destruction. Turlough, while attempting to escape control of the Black Guardian, ends up aboard the Buccaneer, and meets the Eternal Captain Wrack, professing his desire to join her crew and learning she too is working for the Black Guardian. He finds equipment aboard her ship that appears to be the source of the device destroying the other ships and hears the Black Guardian's voice nearby. Later, Wrack offers the Edwardian officers a reception aboard her ship. During the reception, Turlough demonstrates the Wrack's advantage-providing equipment to the Doctor, while Wrack hypnotizes Tegan and implants Tegan's tiara (Tegan and Marriner attend Captain Wrack's reception in full Edwardian costume) with a red crystal. After the reception and continuation of the race, the Doctor sees the Buccaneer nearing the Edwardian ship, determines that the red crystal is used as a focal point of the weapon, and gets rid of the tiara before Wrack can destroy the ship. Nearing the end of the race, the solar winds dissipate and the Buccaneer pulls ahead of the Edwardian ship. Not wishing to see Wrack win, the Eternals return the TARDIS to the Doctor, allowing him to travel to the Buccaneer. However, he is captured, and Wrack's first mate suggests that the Doctor be thrown overboard. From the Edwardian ship, Tegan and the others watch as two bodies are ejected from the Buccaneer just before it crosses the finish line. The ships and their human crews are returned to Earth and the Guardians dismiss the other Eternals. It is revealed that the Doctor won the race, with Wrack and her first mate having suffered "an unfortunate accident". The Doctor refuses the prize, but as Turlough helped the Doctor, he is entitled to a portion of the prize. The Black Guardian reminds Turlough of their bargain, and says that he can give up the diamond, or sacrifice the Doctor to gain both Enlightenment and the TARDIS. Turlough hurls the diamond at the Black Guardian, who vanishes in screams and flames. The Doctor points out that Enlightenment was not the diamond, but the choice itself. Continuity To commemorate the show's anniversary, every story during Season 20 included the return of an enemy