Whatever you do, do not eat those mince pies! They're poisoned, I -oops! I should not have said that.
Listen, you're right. I was planning a murder. But to my surprise, Stinch was already long dead by the time I arrived in his room at 10pm. I swear I did not kill the miserable old man. The mince pies hadn't even finished baking by the time he was dead.
Where did I get the poison? Oh! Hubert, downstairs. He runs an apothecary and keeps all sorts of chemical concoctions to hand. He's something of a chemical genius if you ask me; he experiments with all sorts in his spare time.
Anyway, enough about poison. If you haven't figured out my motive yet, I'm not saying a thing until you figure it out yourself! I think I might listen to some music instead...