The Curse of the Black Spot by a Siren-like creature who marks people with black spots on their palms after they are injured and appears to disintegrate them with her touch after putting them in a trance. Rory Williams receives a cut during a tussle with the pirates, and finds a black spot on his hand, but is prevented from succumbing to the song of the Siren by Amy Pond and the Doctor. Surmising the Siren is using water as a portal, the Doctor instructs the crew to seek refuge in the ship's dry magazine. There, they find Toby Avery, the son of the ship's captain
Carom billiards have a higher light sensitivity to green than to any other color, so green cloth permits play for longer periods of time without eye strain. Modern billiard balls are made from highly resilient plastics with a typical diameter of . They are significantly larger and heavier than their pocket billiards counterparts, ranging between with a typical weight of . While UMB, the International Olympic Committee-recognized world carom billiards authority, technically permits balls as small as , no major manufacturer produces such balls any longer, and the "de facto" standard is . The three standard balls in most carom billiards games