It pained Phineas to watch Eliza run in her condition, but his mind told him it was necessary. He picked up the pace and soon they were running rapidly through the jungle. The trees thickened and the path blurred as they got deeper in, but the knowledge of what lay behind them pushed aside all hesitations. The island itself was several miles wide, but only a little over one mile across. Before long, they had ascended the rocky incline that marked the middle. As they neared the top, Phineas's eye caught sight of a gap in one of the rock formations, partially obscured by vines. 
"Is that the cave?" he asked Eliza, gasping for breath.