Bill was a human. He was married to Mary.
In May 1927 Mary and Bill both lived together in a house in Hampshire, three miles away from the next village. One night it knocked on their door.[statement unclear] Two Groog stood outside.
A short time later Rory Williams arrived at the house. He had lost Amy Pond and the Eleventh Doctor. Then it seemed that they were all attacked by enermies that they could not see. Together Rory, Bill, Mary and the Groog tried to fight the enermies.
However, the enermies were Amy and the Doctor who were trapped in another dimension and tried to contact Rory, Bill and Mary. Amy and the Doctor thought the Groog were the enemies and tried to help Rory and the others.
After Amy and the Doctor returned from their dimension Bill and Mary invited Amy, Rory, the Doctor, Lan and his friend to breakfast and everyone accepted the invitation. (AUDIO: The Empty House)