It has disappeared, Chris, because I am a complete idiot.
Instead of just deleting a surplus thread, I clicked Ban Ip instead. I am so used to clicking Ban Ip when I go into that particular screen because of the kitchens. My brain just went into auto and the milli-second after I clicked it, I knew I had made a major boo boo. My ex-Convent Headmistress, Sister Pauline, would NOT have approved the language I used.
I will try and Unban Chiaroscuro as soon as possible. I emailed him straightaway and he was very polite in his reply!