But Monica's long legs already dangled on the far side, and she dropped successfully if painfully into a clump of thistles, and followed her brother down the bank. There was no doubt about the excellence of the ferns, but they had one disadvantage; like most botanical specimens of any value, the best and finest grew out of reach. There was nothing for it but to climb the wall. They had all three mounted up some distance, and were busily pulling at roots, when a stern voice suddenly sounded in their ears. "What are you doing up there? Get down at once!" Lorraine was so startled that she lost her footing, and descended with more speed than elegance, tumbling indeed almost into the arms of their indignant questioner. He eyed her suspiciously, and turned to Mervyn and Monica, who had come down with greater caution. "Now you three've got to give an account of yourselves," he proclaimed. "I'm a special constable, and I want to know what you're doing on the railway line at the mouth of a tunnel." "We were doing no harm," answered Mervyn, "only getting a few ferns." "Oh, I dare say! And what else? This is a military area, and trespassing on the railway line, and especially loitering in the vicinity of a tunnel, comes under the heading of an offence against the realm. I shall have to report it. Give me your names and addresses." The three young Forresters looked at one another in dismay. "This is absurd!" burst out Lorraine. "We came to get a few ferns, that's all. They're wild, and surely taking a root or two isn't an offence against the realm?" "You've been found in a forbidden area in a military zone," returned the special constable pompously. "I'm stationed here to guard the tunnel, and I shall report you. If you don't give me your names and addresses, I shall have to arrest you." Very unwillingly the Forresters complied, and watched the incriminating details being jotted down in an official notebook. "Our father is a town councillor," ventured Lorraine, hoping for vicarious favour. "That makes it so much the worse, for you ought to know better," was the uncompromising reply. "Take yourselves off at once, and mind you never come trespassing here again!" Crestfallen, but trying to preserve the family dignity, the Forresters beat a retreat. They scorned to run, and walked leisurely up the bank, while the special constable covered them with his eye. Monica had an uneasy suspicion that they might also be covered with a revolver, and, though she would not for worlds have shown a qualm of fear before Mervyn, she was nevertheless considerably relieved when she found herself upon the safe side of the fence. "Strafe the old chap and his jaw-wag!" exploded Mervyn. "A nice mess he's got us into with his fussy interference!" "Do you think he'll really report us?" asked Lorraine anxiously.