This story is a sequel to “Their Island Home,” which takes up the adventures of the Swiss Family Robinson at the place where the author of the original narrative dropped them.

“The Swiss Family Robinson” seems to have affected Jules Verne’s literary bent as no other book ever did. It gave him that liking for the lonely island life as the basis of a yarn which is conspicuous in much of his work. In a preface to the story of which this is really a part he tells how firmly New Switzerland established itself in the fabric of his thoughts, till it became for him a real island inhabited by real people. At last he was compelled to write about it, and “Their Island Home” and “The Castaways of the Flag” are the result.

The youth of Europe—many generations of it—owes a big debt to the old romancer who worked for so many years in his turret room at Amiens to entertain it. From that room, with its many bookshelves, came volume after volume of adventure, mostly with a big admixture of the scientific. M. Verne was not one of those who pile hairbreadth escapes one upon another till they become incredible. There are plenty of things happening in his books, but they are the sort of things that would happen, given the circumstances, and he explains why and how they chanced in the most convincing manner possible. In these days of submarines and aeroplanes it is interesting to read again the wonderful Frenchman’s forecast of them in such books as “Twenty Thousand Leagues under the Sea” and “The Clipper of the Clouds.” “Round the World in Eighty Days”—the task would be an easy one now, but at the time when he wrote it required great ingenuity to make it seem possible; and the end of that book is one of the most ingenious things in fiction, though it has for justification a simple geographical fact. Phineas Fogg was a day late, as he believed. He had apparently lost his wager. But, having gone round the world in the right direction, he had gained a day, and just won. If he had gone the other way he would have been two days late, for a day would have been lost to him—cut right out of the calendar!

The cryptogram which forms the main feature of “The Giant Raft”—the deflection of the compass in “Dick Sands,” which causes the people on the ship of which Dick had to take command to reach the coast of Africa, while believing that they had landed on the American continent—the device of the millionaire in “Godfrey Morgan,” which provided an island with beasts of prey not native to it—the gigantic projectile which carried those intrepid voyagers to the moon and round it—the reaching of the interior of the earth by a road down the crater of one volcano and the return to the surface up the crater of another—these are imaginations not readily forgotten. And the other stories—“Five Weeks in a Balloon,” “The Adventures of Three Englishmen and Three Russians,” “The Tribulations of a Chinaman,” the yarns dealing with the Indian Mutiny, “Michael Strogoff the Courier of the Czar,” and the rest—how entrancing they were, and still are to a boy, or a man with something of the boy yet in him!

Readers of the present book who have not read that named above—though all should read it as well as this—will have no difficulty in joining the story of the castaways to “The Swiss Family Robinson” with the help of the brief sketch of its contents which follows.

The story begins with the arrival of the Unicorn, a British corvette commanded by Lieutenant Littlestone, whose commission includes the exploration of the waters in which New Switzerland is situate. He has with him as passengers Mr. and Mrs. Wolston and their daughters Hannah and Dolly.

When the Unicorn weighs anchor again Mr. Wolston and his wife and their elder daughter, Hannah, remain on the island. But the corvette takes away Fritz and Frank Zermatt and Jenny Montrose, who are all bound for England, where Jenny hopes to find her father, Colonel Montrose, and the two young men have much business to transact, and Dolly Wolston, who is to join her brother James—a married man with one child—at Cape Town. Mr. Wolston hopes that James, with his wife and child, will agree to accompany Dolly and the Zermatts—by the time they return Jenny will have become Mrs. Fritz Zermatt—to the island and take up their abode there.

The Unicorn gone, those left behind settle themselves down to await her return, labouring meanwhile to make ready the island against the possibility of a number of immigrants. One of their first improvements is a canal for irrigation purposes. Mr. Wolston, a skilful engineer, and Ernest, clever and thoughtful, reader of many books and with a distinct scientific bent, are quite capable of planning such things as this.

There are seven people left on the island—M. and Mme. Zermatt, Mr. and Mrs. Wolston, Jack Zermatt, adventurous and keen on sport, Ernest, and the charming Hannah. Between these last two a strong affection develops. The brothers, very unlike in nature, have little in common, but are good friends in spite of that fact; and the whole seven form practically one united and very happy family.

Only a small part of the island has ever been really explored during the ten years the Zermatts have been there. They now determine to find out more about it. In their pinnace, the Elizabeth, they voyage to a hitherto unknown coast, and, after a very arid stretch, find the mouth of a river, capable of floating the pinnace. They christen this the Montrose, in compliment to Jenny.

To the south they see a great mountain range. In order to get as near this as possible Mr. Wolston and Ernest make a canoe trip up the Montrose, but are stopped at length by rapids and a great natural dam.

They all return to Rock Castle and face the dull days of the rainy season, which proves more stormy than usual, and does some damage to their possessions elsewhere than at Rock Castle. That season over, they make preparations for another expedition—this time wholly by land, and made by Mr. Wolston, Jack, and Ernest only, M. Zermatt remaining with the three ladies.

The three are determined to reach the topmost peak of the mountain range, and after some considerable difficulty they achieve their object. They plant the British flag there, Lieut. Littlestone having provisionally taken possession of the island in Great Britain’s name, and they christen the mountain crest Jean Zermatt Peak. From it they discern out at sea a ship flying the British colours. But she disappears, to their intense disappointment.

At Rock Castle those left behind grow anxious when the time the explorers had expected to be away lengthens itself by several days. Then Mr. Wolston and Ernest turn up—without Jack.

That adventurous young man has wandered off after three elephants, in the hope of capturing and taming the calf after killing the father and mother. They have searched in vain for him, and are almost forced to the conclusion that something tragic must have happened.

But Jack turns up, safe and sound. He has, however, an alarming tale to tell. It would seem that their days of peace on the island are numbered. He has been captured by savages, and, though he has escaped by adroit courage, all know that the chance of the savages finding the Promised Land is one with which they must reckon.

The Unicorn is now past the time appointed for her return, and the seven have thus a double reason for anxiety.

Here “Their Island Home” finishes, and in the present book may be read what came of it all, and in what way they emerged from heavy trouble into peace and prosperity even greater than of old.