At this moment he heard the approaching step, and turned round sharply.  The detective saw that his face was ghastly pale in the moonlight, and his brows wrinkled in anger.

“What the devil do you want?” he burst out, as Gorby paused.

“What do you mean by following me all over the place?”

“Saw me, watching the house,” said Gorby to himself.  “I’m not following you, sir,” he said aloud.  “I suppose the pier ain’t private property.  I only came down here for a breath of fresh air.”

Fitzgerald did not answer, but turned sharply on his heel, and walked quickly up the pier, leaving Gorby staring after him.

“He’s getting frightened,” soliloquised the detective to himself, as he strolled easily along, keeping the black figure in front well in view.  “I’ll have to keep a sharp eye on him or he’ll be clearing out of Victoria.”

Brian walked rapidly up to the St. Kilda station, for on looking at his watch he found that he would just have time to catch the last train.  He arrived a few minutes before it started, so, getting into the smoking carriage at the near end of the platform, he lit a cigarette, and, leaning back in his seat, watched the late comers hurrying into the station.  Just as the last bell rang he saw a man rush along, to catch the train.  It was the same man who had been watching him the whole evening, and Brian felt confident that he was being followed.  He comforted himself, however, with the thought that this pertinacious follower might lose the train, and, being in the last carriage himself, he kept a look out along the platform, expecting to see his friend of the Esplanade standing disappointed on it.  There was no appearance of him, so Brian, sinking back into his seat, lamented his ill-luck in not shaking off this man who kept him under such strict surveillance.

“Confound him!” he muttered softly.  “I expect he will follow me to East Melbourne, and find out where I live, but he shan’t if I can help it.”

There was no one but himself in the carriage, and he felt relieved at this because he was in no humour to hear chatter.

“Murdered in a cab,” he said, lighting a fresh cigarette, and blowing a cloud of smoke.  “A romance in real life, which beats Miss Braddon hollow.  There is one thing certain, he won’t come between Madge and me again.  Poor Madge!” with an impatient sigh.  “If she only knew all, there would not be much chance of our marriage; but she can never find out, and I don’t suppose anyone else will.”

Here a thought suddenly struck him, and rising out of his seat, he walked to the other end of the carriage, and threw himself on the cushions, as if desirous to escape from himself.

“What grounds can that man have for suspecting me?” he said aloud.  “No one knows I was with Whyte on that night, and the police can’t possibly bring forward any evidence to show that I was.  Pshaw!” he went on, impatiently buttoning up his coat.  “I am like a child, afraid of my shadow—­the fellow on the pier is only some one out for a breath of fresh air, as he said himself—­I am quite safe.”