No ordinary ship
The Doctor and companion Vislor Turlough explore their current location for clues. Seperately, companion Tegan encounters a ship's first mate and he takes her to the bridge. Tegan is confused by the appearance of equipment from another time zone on what appears to be an Edwarding sailing ship. The Doctor and Vislor enter just as the captain orders an update on their position. The viewing screen opens to reveal that they are on a massive historical sailing ship... floating in space! Classic Doctor Who clip from episode 1 of Enlightenment.
A meeting of Dark and Light
The Black Guardian and The White Guardian clash as The Doctor enters with news has docked the ship safely. For doing so The Doctor and Vislor are entitled to a portion of the prize of the space ship race, a massive diamond. The Doctor declines, 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.