“You are committing yourself to endless and unnecessary trouble, Mr. Gianapolis, but if you really wish to do as you suggest, let it be so. Good night!”

She barely touched his extended hand, turned, and ran fleetly back toward the door of Palace Mansions. Ere reaching the entrance, however, she dropped a handkerchief, stooped to recover it, and glanced back rapidly.

Gianapolis was just turning the corner.

Helen perceived the unmistakable form of Denise Ryland lurking in the Palace Mansions doorway, and, waving frantically to her friend, who was nonplussed at this change of tactics, she hurried back again to the corner and peeped cautiously after the retreating Greek.

There was a cab rank some fifty paces beyond, with three taxis stationed there. If Gianapolis chartered a cab, and she were compelled to follow in another, would Denise come upon the scene in time to take up the prearranged role of sleuth-hound?

Gianapolis hesitated only for a few seconds; then, shrugging his shoulders, he stepped out into the road and into the first cab on the rank. The man cranked his engine, leapt into his seat and drove off. Helen Cumberly, ignoring the curious stares of the two remaining taxi-men, ran out from the shelter of the corner and jumped into the next cab, crying breathlessly:

“Follow that cab! Don't let the man in it suspect, but follow, and don't lose sight of it!”

They were off!

Helen glanced ahead quickly, and was just in time to see Gianapolis' cab disappear; then, leaning out of the window, she indulged in an extravagant pantomime for the benefit of Denise Ryland, who was hurrying after her.

“Take the next cab and follow ME!” she cried, whilst her friend raised her hand to her ear the better to detect the words. “I cannot wait for you or the track will be lost”...