Professor Moriarty

They were in this house.

I found a nice little culture of them in a glass of Cobb's Foot Jelly, which was on the table in the front room.

How they ever survived, as long as this, I can't imagine.

But here, gentlemen, come into my laboratory.

I want to show you what I've done with them.

Here we are, gentlemen.

Quite a nice, modern little outlay for such an ancient house.

Yes, it is an ancient house, Professor.

But here, this little test tube, it contains enough of the Black Plague to wipe out the entire city of Edinburgh.

Yes, I rather thought that was your purpose.

Yes, Mr. Holmes, experiments that might have saved the world a great deal of suffering.

They only killed the refuse of the city, beggars, scum.

Quite, but they met the hangman nonetheless.

Aye, the fools.

What price the death of a few... when we might have discovered a cure that would have saved all humanity.

Humanity.

Bah!

I hate it.

Ever since then, I'd sworn I'd get revenge on humanity... and the law-abiding citizens of Edinburgh in particular.

And now... the time has come.