"H'm, telephone wire," muttered Denbigh. "That doesn't look as if the ship has cleared out. More than likely they've landed some of the guns to form a masked battery. It strikes me pretty forcibly that we'll have to investigate at both ends of the wire." Not until the sound of the receding footsteps had died away--and it took an exasperating time--did the subs emerge from their place of concealment. The air was now almost free from mist. Occasionally patches of vapour drifted across their path, but generally speaking the miasmic belt ended at a distance of about half a mile from the sea. O'Hara stooped and lifted up the wire. "Let's cut the dashed line," he suggested. "All in good time," replied Denbigh. "If we do so now they'll be buzzing around before we've made our investigations. I think we're on to a good thing." Nearer and nearer grew the sound of the motor, until upon emerging from the grove the subs found themselves within a hundred yards of a German base. At this point the ground sloped gently to the edge of the lagoon. Without any apparent attempt at concealment two searchlights had been set in position. A dozen men in naval uniforms were standing around the projectors. The lights were "running" as was evident from the crackle of the carbons, but the shutters were closed, cutting off the rays. The current was produced by a dynamo, the power being supplied by means of the petrol motor, the pulsations of which had given the subs a clue to its position. "What's the idea?" whispered O'Hara, indicating the unconcealed searchlight. "A blind," replied his companion. "I guessed it. We'll carry on a little farther before we retrace our steps." Another _détour_ was necessary, but on plunging into the mangrove forest on to the other side of the clearing the Irishman's foot tripped in the telephone wire. "Good!" he ejaculated. "You're right, old man." Five hundred yards farther on the explorers almost tumbled into a deep pit, protected on the seaward side by sandbags, between which were stuck shrubs and branches of trees to screen the artificial work from seaward. In the pit were two quick-firers, with basket cases of ammunition in readiness. Pacing up and down between the guns was a sentry, while under a tarpaulin supported by short poles were about a dozen sleeping men. Farther on was another excavation, but what it contained the British officers were unable to ascertain. The battery, it was evident, was manned by some of the reservists from the _San Matias_. Denbigh, having taken a compass bearing of the entrance of the lagoon, nudged his chum, and they began to retrace their steps. Moving as rapidly as their sense of caution would permit, they again skirted the searchlight station and picked up the telephone wire trail in the woods beyond. "We must not forget the time," cautioned the Irishman.