'You 'op it,' concluded the man in blue. 'That's what you do. You 'op
it.'

'I should,' said Psmith kindly. 'The officer is speaking in your best
interests. A man of taste and discernment, he knows what is best. His
advice is good, and should be followed.'

The constable seemed to notice Psmith for the first time. He turned and
stared at him. Psmith's praise had not had the effect of softening him.
His look was one of suspicion.

'And what might _you_ have been up to?' he inquired coldly. 'This
man says you hit him.'

Psmith waved the matter aside.

'Purely in self-defence,' he said, 'purely in self-defence. What else
could the man of spirit do? A mere tap to discourage an aggressive
movement.'

The policeman stood silent, weighing matters in the balance. He
produced a notebook and sucked his pencil. Then he called the conductor
of the tram as a witness.

'A brainy and admirable step,' said Psmith, approvingly. 'This rugged,
honest man, all unused to verbal subtleties, shall give us his plain
account of what happened. After which, as I presume this tram--little
as I know of the habits of trams--has got to go somewhere today, I
would suggest that we all separated and moved on.'