Origin
Sylvia Manners aka the Black Angel lived in a castle near London (where she kept her plane in an underground hangar). Yet, in the middle of her large, fortified, solid stone residence, she excused not answering her aunt’s knock on her bedroom door (while she’d been out for Black Angel action) by claiming she’d been afraid the polite knock was from Nazis, calling on her for purposes of ravishment. Later she excused herself for more Black Angel action with a story about having an attack of the wim-wams in the middle of a peaceful train ride; and she’d characterized herself as so delicate and sensitive, the aunt bought it.