I only know that Philip will never forget it.

Just think of all the things you could do on a magic island if you were there with your dearest dear, and you'll know how Philip spent his time.
He enjoyed every minute of every hour of every day, and, best thing of all, that week made him understand, as nothing else could have done, that Helen still belonged to him, and that her marriage to Mr.Graham had not made her any the less Philip's very own Helen.
And then came a day when Philip, swinging in a magnolia tree, looked out to sea and cried out, 'A sail! a sail! Oh, Helen, here's the ark! Now it's all over.

Let's have Lucy to stay with us, and send the other people away,' he added, sliding down the tree-trunk with his face very serious.
'But we can't, dear,' Helen reminded him.

'The island's ours, you know; and as long as it's ours no one else can land on it.

We made it like that, you know.' 'Then they can't land ?' 'No,' said Helen.
'Can't we change the rule and let them land ?' 'No,' said Helen.
'Oh, it _is_ a pity,' Philip said; 'because the island is the place for islanders, isn't it ?' 'Yes,' said Helen, 'and there's no fear of the sea here; you remember we made it like that when we made the island ?' 'Yes,' said Philip.