"Very likely not," Wilfrid said coldly. "But the fact remains that I was once in Mr. Flower's service as doctor on one of his boats. I am much obliged to you for your information, which will save me a great deal of trouble in the morning."
Wilfrid strolled away quite naturally and easily; indeed, he was so cool and collected that the sergeant allowed him to depart with a curt good-night. There was just the chance that the officer might change his mind, so that Mercer sped on rapidly back to Gower Street, nor did he breathe freely till he stood once more outside the gate over which he had helped Uzali to climb. It struck Wilfrid as being a good idea that he should climb the gate himself and stay till the square keeper came in the morning to unlock the gates. No sooner had this idea occurred to him than he proceeded to put it into operation. He dropped quietly on to the path on the other side and settled himself down to wait in patience for Uzali to reappear. Twice did he walk the circuit of the garden. Twice did he pass Samuel Flower's house; the brass numbers on the door shone so steadily under the street lamp that there was no mistaking it. The house appeared to be in darkness save one light in an upper room, which flickered every now and again as if a window had been opened and the draught had caused the gas to flare unsteadily. There was nothing for it but to wait with what patience he possessed, although Wilfrid was getting tired of his adventure. He was wondering if it would be safe to light a cigarette to pass the time away. He looked around him and saw in the centre of the garden a dense mass of bushes where he might conceal himself and smoke without the faintest chance of detection.
He made his way across the grass, and as he reached the shelter of the thicket he seemed to hear some one breathing stertorously. Shading the vesta in his hand he swept the shining blue flame over the grass. There was the outline of a figure lying on its back with a pale face turned up to the sky.
"Good Heavens!" Mercer cried, "why, it's Uzali!"
At the mention of his name the Malay opened his eyes and looked drearily about him. There was a nasty cut on the side of his head and a big black bruise under the left eye. It did not take Mercer long to discover that his companion was suffering from loss of blood, but so far as he could see no very great harm had come to him. A minute or two later Uzali staggered to his feet.
"How did it happen?" Wilfrid exclaimed.
Uzali put the question aside impatiently.
"Don't ask me now," he whispered. "Get me home as soon as you can. I will tell you about it in the morning. No, you are not to come home with me. You will put me in a cab and send me straight round to my flat. I can summon my own doctor by telephone and no one will be any the wiser. Now do you think you could manage to get me over that gate?"
There was something so imperious in Uzali's manner that Wilfrid asked no questions. By the great exertion of strength he managed to lift Uzali over the gate and deposit him on the coping-stones outside. A sleepy driver of a hansom cab came plodding along and Mercer summoned him without delay.
"My friend has had an accident," he said. "Here is his card and address. I want you to get him home as soon as possible and see him into his flat. You will have nothing more to do after that except to mind your own business and ask no questions. Come, my good man, I don't suppose you will mind earning a five-pound note like that. It isn't much for the money."