“Fortunately,” said Psmith, “there is no necessity to remain in a state of doubt. I can give you an unfailing method by means of which you may discover if she is what she would have us believe her.”
“What’s that?”
“Kiss her.”
“Kiss her!”
“Precisely. Go to her and say, ‘Susan, you’re a very pretty girl . . .’”
“But she isn’t.”
“We will assume, for purposes of argument, that she is. Go to her and say, ‘Susan, you are a very pretty girl. What would you do if I were to kiss you?’ If she is a detective, she will reply, ‘How dare you, sir!’ or, possibly, more simply, ‘Sir!’ Whereas if she is the genuine housemaid I believe her to be and only sweeps under bureaux out of pure zeal, she will giggle and remark, ‘Oh, don’t be silly, sir!’ You appreciate the distinction?”
“How do you know?”
“My grandmother told me, Comrade Threepwood. My advice to you, if the state of doubt you are in is affecting your enjoyment of life, is to put the matter to the test at the earliest convenient opportunity.”
“I’ll think it over,” said Freddie dubiously.