"To begin with," said Tuppence, "what have we to go upon?"

"Absolutely nothing," said Tommy cheerily.

"Wrong!" Tuppence wagged an energetic finger. "We have two
distinct clues."

"What are they?"

"First clue, we know one of the gang."

"Whittington?"

"Yes. I'd recognize him anywhere."

"Hum," said Tommy doubtfully, "I don't call that much of a clue.
You don't know where to look for him, and it's about a thousand
to one against your running against him by accident."

"I'm not so sure about that," replied Tuppence thoughtfully.
"I've often noticed that once coincidences start happening they
go on happening in the most extraordinary way. I dare say it's
some natural law that we haven't found out. Still, as you say, we
can't rely on that. But there ARE places in London where simply
every one is bound to turn up sooner or later. Piccadilly Circus,
for instance. One of my ideas was to take up my stand there
every day with a tray of flags."

"What about meals?" inquired the practical Tommy.