I apologize sincerely as if I am asking here about the Holmes' series quotations.
Now, I stumbled upon a "new phrase" to me.
The note was undated, and without either signature or address.
"There will call upon you to-night, at a quarter to eight o'clock [it said], a gentleman who desires to consult you upon a matter of the very deepest moment. Your recent services to one of the royal houses of Europe have shown that you are one who may safely be trusted with matters which are of an importance which can hardly be exaggerated. This account of you we have from all quarters received. Be in your chamber then at that hour, and do not take it amiss if your visitor wear a mask.
The "standard" English I have learned for so many years, when you would like to express the existence of something, ( in the future case, )
There will be + noun.
Is this as I am asking at the title, the 19th or 20th century British expression or the reflection of the age?