Mike went on searching his pockets, and at last gave an exclamation of relief. The couple of tiny screws which he had carefully wrapped in a piece of paper and then mislaid had come to light. He took them out, and then threw down the piece of paper, which fluttered to the ground. The Lieutenant idly picked it up, his thoughts far away on those visionary battlefields, and glanced absentmindedly at the print. It was a notice issued by the North British Railway, and read as follows:-- "FIVE POUNDS reward will be paid to anyone giving information leading to the arrest and conviction of the person or persons who on the night of the 4th inst. caused disfiguring paint marks to be made on the railway track and girders of the Forth Bridge." Lawless was not a Sherlock Holmes, so he did not try to draw inferences or make deductions from the statement he had just read. Still, it puzzled him. Why should any "person or persons" employ their leisure moments in dabbing paint on the girders and track of the Forth Bridge? Lawless tossed the paper aside, and, for a time at least, forgot all about the notice. It was not till later on that he had occasion to recall it. "I expect we shall have to go out to-night, Mike, so have everything ready," he said, rising to his feet. "I will that, yer honour!" answered Mike, turning a hot and beaming face upon his superior. As he had anticipated, Lawless received orders to set out at eight o'clock that night on a scouting expedition. Although the public was kept in ignorance of the fact, the military authorities were nightly expecting a German attack on Rosyth. Every precaution had been taken to render such an attack abortive, and the entrance to the Forth was guarded by destroyers and submarines. Still, the seemingly impossible sometimes happens in time of war, and there was always a chance that the enemy might creep through the defences by some means or other. Already an apparently harmless merchant steamer had been stopped off Leith, and, upon examination, found to be chock-full of dynamite ready to be fired by time-fuses. No doubt this would have been exploded under the Forth Bridge, with the result that no warships could have entered or left Rosyth till the river mouth had been cleared of the _débris_. As an additional precaution, therefore, two or three aeroplanes were sent out nightly to scout along the coast from Fife Ness to St. Abb's Head. The aviators so employed found it a monotonous, unexciting task in which, so it seemed, neither glory nor promotion was to be earned.