How suddenly the darkness was falling! Orissa leaned from her seat and found the water had turned to a color nearly as black as ink. Beneath her the bow of the aluminum motor boat was so depressed that it was almost even with the water and as it bobbed up and down with the waves it was shipping the inky fluid by the dipperful.
She scrambled out of the seat, then, to step gingerly over the unlucky chest and crouch upon a narrow seat of the little boat, near the stern.
"Come, Sybil," she called; "and be very careful."
Sybil promptly descended to the boat, which now rode evenly upon the waves. In this position the propeller was just under water and the engine rested over the center of the light but strong little craft. But propeller and engine were alike useless to them now. Overhead the planes spread like huge awnings, but they carried so little weight that they did not affect the balance of the boat.
"Steve planned well," murmured Orissa, with a sigh. "If only he had never thought of that dreadful chest, we would not be in this fix."
As she spoke she kicked the chest a little resentfully with her foot, and it seemed to move. Sybil leaned forward to eye it as closely as the gathering darkness would allow.
"Why, Ris," she exclaimed, "the thing has come loose. Help me to tip it up."
Between them they easily raised the chest to its former position, where it rested just before them. Steve had bolted it at either end, but one of the bolts had broken away and the other had bent at almost a right angle. Perhaps this last bolt would have broken, too, had not the chest, in falling, become wedged against the braces.
"This horrid box has heretofore been our dire enemy," remarked Sybil; "but let us be forgiving and encourage it to make amends—for it holds eatables. How does the cover open, Ris?"
Stephen had shown Orissa how to work the sliding catch and in a moment the girl had the lid open and held it upright while Sybil searched within.