He tried to feel at his ease and secure

He tried to feel at his ease and secure, but presently the indefinable restlessness of the social animal in solitude distressed him. He began to want to look over his shoulder, and, as a corrective, roused himself to explore the rest of the island.
It was only very slowly that he began to realise the peculiarities of his position, to perceive that the breaking down of the arch between Green Island and the mainland had cut him off completely from the world. Indeed it was only when he came back to where the fore-end of the Hohenzollern lay like a stranded ship, and was contemplating the shattered bridge, that this dawned upon him. Even then it came with no sort of shock to his mind, a fact among a number of other extraordinary and unmanageable facts. He stared at the shattered cabins of the Hohenzollern and its widow's garment of dishevelled silk for a time, but without any idea of its containing any living thing; it was all so twisted and smashed and entirely upside down. Then for a while he gazed at the evening sky. A cloud haze was now appearing and not an airship was in sight. A swallow flew by and snapped some invisible victim. "Like a dream," he repeated.
Then for a time the rapids held his mind. "Roaring. It keeps on roaring and splashin' always and always. Keeps on...."
At last his interests became personal. "Wonder what I ought to do now?"
He reflected. "Not an idee," he said.
He was chiefly conscious that a fortnight ago he had been in Bun Hill with no idea of travel in his mind, and that now he was between the Falls of Niagara amidst the devastation and ruins of the greatest air fight in the world, and that in the interval he had been across France, Belgium, Germany, England, Ireland, and a number of other countries. It was an interesting thought and suitable for conversation, but of no great practical utility. "Wonder 'ow I can get orf this?" he said. "Wonder if there is a way out? If not... rummy!"
Further reflection decided, "I believe I got myself in a bit of a 'ole coming over that bridge....
"Any'ow--got me out of the way of them Japanesy chaps. Wouldn't 'ave taken 'em long to cut MY froat. No. Still--"
He resolved to return to the point of Luna Island. For a long time he stood without stirring, scrutinising the Canadian shore and the wreckage of hotels and houses and the fallen trees of the Victoria Park, pink now in the light of sundown. Not a human being was perceptible in that scene of headlong destruction. Then he came back to the American side of the island, crossed close to the crumpled aluminium wreckage of the Hohenzollern to Green Islet, and scrutinised the hopeless breach in the further bridge and the water that boiled beneath it. Towards Buffalo there was still much smoke, and near the position of the Niagara railway station the houses were burning vigorously. Everything was deserted now, everything was still. One little abandoned thing lay on a transverse path between town and road, a crumpled heap of clothes with sprawling limbs....
"'Ave a look round," said Bert, and taking a path that ran through the middle of the island he presently discovered the wreckage of the two Asiatic aeroplanes that had fallen out of the struggle that ended the Hohenzollern.