Penny Dreadful, Season 3

Catriona:
Mr. Chandler, you will need a mask, something to filter the air.

Ethan:
I can handle the fog.

Catriona:
That is not fog. That's what we all thought at first: an especially dense fog mixing with the chlorine gases from the factories. And then people started to die. First by the dozens, then by the hundreds. Last week, 7,000 people died in London. It is not a fog, Mr. Chandler. It is a plague.

Ethan:
I'll take my chances. He needs a doctor. I need to find Miss Ives.

Catriona:
We all need to find Miss Ives. If I'm correct, she is the only one who can stop all this.

Ethan:
And what is "all this"?

Catriona:
The End of Days.