“Good morning, Mr. Whittington,” she said politely. “At least, au revoir , I should say.”

“Exactly. Au revoir! ” Whittington looked almost genial again, a reversion that aroused in Tuppence a faint misgiving. “ Au revoir , my clever and charming young lady.”

Tuppence sped lightly down the stairs. A wild elation possessed her. A neighbouring clock showed the time to be five minutes to twelve.

“Let’s give Tommy a surprise!” murmured Tuppence, and hailed a taxi.

The cab drew up outside the tube station. Tommy was just within the entrance. His eyes opened to their fullest extent as he hurried forward to assist Tuppence to alight. She smiled at him affectionately, and remarked in a slightly affected voice:

“Pay the thing, will you, old bean? I’ve got nothing smaller than a five-pound note!”