Mortimer must be a daily chatterbox, because all his mom says when
she puts him to bed (throws him in bed in the book, I don't like
that part so I edit it to be a little less antagonistic) is BE
QUIET.
Well, I know little ones, and you know little ones, and we all know
little ones, and Mortimer says yes but immediately does what he
shouldn't. He sings. Loudly. He's gonna make his noise all day
long.
So his whole family, and ultimately the cops troop up to tell him
to be quiet, and while they fight over whose responsibility it is
(and stop paying him attention for singing), he falls asleep.
The ending is a bit predictable, isn't it? But for a bedtime book,
as I think this is, that sort of ending is just what you need. Nice
and predictable and quick