Mr R was the mysterious owner of a mansion. He invited a few guests to see the presentation of a ram's skull in one of his rooms. He hoped to use Abigail as a medium to contact another plane and achieve immortality.
While everyone was seated at the table, including the First Doctor, Ian Chesterton and Barbara Wright, he asked them to all stare at the ram. Something evil tried to enter through Abigail, but the Doctor and Edgar Allan Poe destroyed the skull.
Later, Mr R arranged with Abigail's guardian, Mrs Allardyce to invent a story to explain Abigail's death. He asked Poe not to use his name should Poe choose to write about the evening's events. (PROSE: The True and Indisputable Facts in the Matter of the Ram's Skull)