In addition, this story marked the final appearances of the Inquisitor and the Valeyard as recurring characters, and a final appearance of Nicola Bryant as Peri Brown in a cameo to give her character closure under happier circumstances than what the events of Mindwarp had offered. Season 23's finale was the final story to which longtime scriptwriter Robert Holmes contributed. He passed away from illness shortly before its completion. Unfortunately, this would cause the writing process to suffer many setbacks before entering production.