Research
Armed with a notebook and a few copies of Who's Who, I estimated we could learn something about Sherry Vernet.
Lestrade, of course, thought the whole idea was a waste of time.
"It won't be a gentleman," he said, "At least, not one from a titled family and all that. Powerful people do not rise up against the government that made them powerful."
"But," I replied, "bored younger sons of powerful people sometimes become disillusioned. I direct your attention to the recent events in Eastern Europe."
And thus, we commenced our search. Hypothesizing that 'Vernet' or 'Sigerson' might be variations on his real name, I directed Lestrade and Moran to pay special attention to any entry bearing those names. After what seemed like an eternity, Lestrade dropped his copy in shock.
"I will not believe this!" he exclaimed, motioning the two of us to look.
The entry was for one Mycroft Holmes, elder son of a country squire and recently knighted for confidential services to Her Majesty's government.
"You don't think this man would..." Moran began.
"His father's name is Siger. Apparently, Siger Holmes married twice. The first marriage was with a relatively minor member of the Russian aristocracy who moved here following rumors of assassination attempts. That ended in the death of Lady Alexandra due to complications from childbirth. Hmm. The second was with--"
Lestrade interrupted. "An artist named Cecile Vernet!"
"Indeed," I continued, "So Mycroft Holmes is half-blood, then. Most interesting. And any younger siblings he may or may not have would be from the second marriage, and therefore entirely human."
The entry on Holmes went on for some time, detailing his founding of the Diogenes Club and involvement in several matters of national security. None of the specifics could be published, of course, but the editors of the volume certainly conveyed a respect for the man's...er, being's prestige. It was the last line, however, that was cause for alarm.
Relatives: William Sherlock Scott Holmes (Half-brother). Whereabouts unknown.
"It appears, gentlemen," I announced, "that we will be paying a visit to the Diogenes Club."