So this is a book set in old England, roughly Sherlock Holmes era, although I don't think it was written that far in the past. This book is apparently NOT The Italian Secretary by Caleb Carr, which is what I thought it was, but having just flipped through it can't find the part I'm thinking of.

There's a scene where two characters are checking into a hotel under assumed names. After giving their fake names they are embarrassed when the hotel clerk identifies their real identities, based on a telegram from one of the character's wives. The wife is irate that her husband has been gone so long and the telegram begins: *insert character name* YOU SWINE. STOP.

Can anyone help me to identify this mysterious tome?