This trench had a head cover formed of cross-beams, overlaid with branches and earth--a sure protection against shrapnel. There was a long bench of telegraph poles, little cupboards for cartridges and kit, and ramps for reclining chairs or couches, and drains to carry off the rain. "Come into our parlor, colonel," invited one of the soldiers, leading the way into a subterranean chamber, which was warmed by a fire in an old perforated petroleum tin. "It is wonderful what ingenuity and labor can accomplish out of the most unpromising material," observed the colonel. "Made in Germany, colonel," laughed one of the veterans, "no matter where you put them." From the business end of the trench a hot meal was speedily produced for the visitors, adding another touch of surprise for Billy. "Well, my lad, we must report to the general," announced the colonel, who had politely denied the petition of the trench veterans that he try one of their couches for the night. "You don't mind an air trip in the dark, do you?" inquired the colonel. "Not a bit," assured Billy, "I've made many a one." It was quite pitch black when the colonel and Billy rode back across the plain, but the horse was sure-footed, and the way was fitfully lighted by the occasional upshoot of rockets that left a long green stream of stars, revealing the now silent battlefield and its dreadful record of uncounted dead. While Billy flourished an electric torch in giving the biplane a careful look over, the colonel bestowed a playful slap on the flank of the faithful horse, which sent the animal trotting up the road. "He knows his number and troop as well as I do, and will go as straight as a die to the feed trough," asserted the colonel. "Are you ready, boy?" "Trim as a ship, colonel." With a flare on the compass, rising high, Billy held the nose of the biplane in the direction of the heights that centered headquarters. Small red sparks glowed in the trenches below, and the upper darkness was ever and anon split by signal rockets and leaping flames of light from countless campfires. Billy, with the aid of the small searchlight in the bow of the biplane, found safe landing, also insuring a sight of the colors to the sentries, who might otherwise be tempted to take a pot shot at the winged, midnight visitor. Henri was the first to hear the whirr of the incoming aircraft, for which he had for hours held an open ear. "Here you are at last!" he exclaimed, making an open-arm break for his flying partner. "You haven't lost an eye, or a leg, or anything, have you?" he anxiously inquired. "Sound as an Uncle Sam dollar, old boy," assured Billy. "But you just bet I'm sleepy." "I believe even Roque was uneasy about you," said Henri, as he insisted on giving Billy's blanket a snug tug.