Bill West is an athletic young American living on an allowance from a
millionaire uncle. The uncle sends him to London to see why his, the
uncle's, business interests are going downhill. Bill takes with him his
best, but hard-drinking, friend Judson Coker, to whose beautiful sister
Bill aspires to be engaged. She had wanted Bill to take Juddy away and keep
him off the drink.
In London Felicia ('Flick') Sheridan, twenty-one, is engaged to Roderick
Pyke, son and heir of Sir George Pyke, founder and proprietor of the
Mammoth Publishing Company. Flick had, as a schoolgirl in America, fallen
in love with a Harvard footballer who had dragged her out of a lake in
which she was foolishly beginning to drown. This was Bill West, and Bill
and Flick meet again in London just when Flick had broken her engagement to
Roderick and, fearing reprisals, has run away from home and disapproving
elders. Flick goes to America. Bill's uncle comes to London. Flick helps
Bill find the man who is robbing his uncle's London till, Wilfred Slingsby.
So...
Here is Wodehouse's first use of Mario's Restaurant where Society dines and
has fracas and where - as at the old Café de Paris - diners downstairs
(Must Dress) cannot see the diners upstairs (Needn't Dress) who can see
them.
Source: Richard Usborne. Plum Sauce. A P G Wodehouse Companion.