A.N. Today's prompt is from Book girl fan:Holmes may not be the world's only consulting detective. This is set pre-Watson. Gregson's point of view.

Dear uncle Raphael,

I write to apologize. When you gave me Poe's book, insisting that you met the person after which Dupin had been modelled, I didn't believe you. Well, I believed you until I read the book.

That you met in Boston a very bright young man in your prime, I could easily accept. That his words offered you an interesting point of view that made you consider a new avenue – the correct avenue – in your investigations more than once I knew it was true. You're not so humble that you would credit your successes to a stranger. Admitting that you asked an amateur's input must not have been easy, so I knew this Douglas March had to be special. Poe wouldn't have picked him out to immortalize in a book otherwise, I guess, even if he changed continent to make sure people's privacy was kept.

But when you insisted that whatever Poe wrote, he'd been understating rather than aggrandising his character's abilities, as writers are wont to do, that I simply couldn't believe after having read the book. I supposed that you wanted to enforce how you were justified in seeking a dilettante's help because he was some sort of godlike being.

As I wrote, I apologize. I must have met your consultant's relative, or disciple, or maybe simply this century is plentiful in extraordinarily clever men. Perhaps these are the forerunners of further progress in the human race's mental capabilities. Long story short, I've met this Holmes fellow and I can finally see that Poe and you weren't necessarily overselling your acquaintance. And I can see why you would go to him in the trickiest circumstances. To be honest, I will probably go to my own genius too. Anything to make sure that justice is served, right, uncle?

Apologetically yours,

Tobias