“I’ll let you know if I feel it coming on,” the Imp assured him.

Had the sentry been a man of swift and penetrating observation—which he wasn’t—he might have asked the question in more serious a tone. For he would have remarked that the Imp’s black eyes were resting lovingly upon a rain-water-pipe, giving to a skilful climber easy access to the terrace underneath the Prince’s windows.

“I would like to see him,” said the Imp.

“Friend o’ yours?” asked the sentry.

“Well, not exactly,” admitted the Imp. “But there, you know, everybody’s talking about him down our street.”

“Well, yer’ll ’ave to be quick about it,” said the sentry. “’E’s off to-night.”

Tommy’s face fell. “I thought it wasn’t till Friday morning.”

“Ah!” said the sentry, “that’s what the papers say, is it?” The sentry’s voice took unconsciously the accent of those from whom no secret is hid. “I’ll tell yer what yer can do,” continued the sentry, enjoying an unaccustomed sense of importance. The sentry glanced left, then right. “’E’s a slipping off all by ’imself down to Osborne by the 6.40 from Waterloo. Nobody knows it—’cept, o’ course, just a few of us. That’s ’is way all over. ’E just ’ates—”

A footstep sounded down the corridor. The sentry became statuesque.

At Waterloo, Tommy inspected the 6.40 train. Only one compartment indicated possibilities, an extra large one at the end of the coach next the guard’s van. It was labelled “Reserved,” and in the place of the usual fittings was furnished with a table and four easy-chairs. Having noticed its position, Tommy took a walk up the platform and disappeared into the fog.