Recently, I came face to face with one of those odd little unsolvable mysteries.
I was ordering an on-line shop including ice cream for the kids, when I noticed that the Morrisons site had somehow put a picture of The Eternity Fund's cover where an ice cream should be. I took a screen shot just to prove to myself I wasn't hallucinating.
Clearly my computer did this, as Morrisons don't sell The Eternity Fund and even if they did, the blue door of Department Thirteen could never be mistaken for a Viennetta.
Happy days!