The Whovian Review #135- The Unquiet Dead

In a Christmas episode that was not aired at Christmas, the Doctor travels to 1869 Cardiff during the Christmas holiday where a rift in time and space creates a real phantom in an opera. Gas creatures who were mostly silent, unless they inhabited the dead, were they themselves a deadly vengeance of revenge. The Gelth as they were named end up crashing a Charles Dickens reading of A Christmas Carol and involving The Doctor, Rose, and Gweneth in a plot of certain doom for the human race. Will Colin be the happy medium?