What the deuce?!

I OED'd the term "deuce" in the sense that Pesca uses it in The Woman in White.

"The personification or spirit of mischief, the devil. Originally, in exclamatory and interjectional phrases; often as a mere expression of impatience or emphasis"

So maybe this is more like saying "WTH"...?

I can't help but picture Stewie Griffin from Family Guy every time I read this phrase :)

[Victorian Literature]