Hubert bent, and striking a match with difficulty, looked at his watch. It wanted eighteen minutes to midnight.

He and his companion had on the way calculated that if they lost no time they could reach Orbetello, which was one of the stopping-places of the night express from Rome for Paris, just before the train was due to arrive.

Twice after leaving the mountains they had news of the car they were chasing, once from a shepherd and again from two mounted carabinieri. If they could reach Orbetello they might prevent Flobecq from leaving.

“We must not yet demand his arrest,” the Englishman said to the man at his side. “If we did then it would result in just the thing we are endeavouring to avoid—exposure!”

“No, signore. We must catch him up and keep in touch with him until you decide what action to take in Her Highness’s interests.”

The chauffeur, urged on by Hubert, drove with reckless speed, with the railway line always on their left, and now and then passing red and green, signals, and the small, lonely houses of the watchmen of the line.

Already in the far distance could be seen the lights of the little town out at the end of a promontory at the foot of the high, dark Monte Argentario, rising straight from the sea, a corner of Italy which no one ever visits, though it is on the direct sea road to Rome.

“At last!” cried Waldron excitedly, pointing out the lights.

“Yes, signore, that is Orbetello!” declared Pucci. “But see,” he added quickly. “See that single light on the left yonder! Is it not moving—coming towards us?”

Hubert strained his eyes in the direction which the detective pointed.