Fire Island, by George Manville Fenn.
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This is good vintage Fenn, with dreadful situation following dreadful
situation, and the heroes (mostly) managing to get out of it somehow.
Right up to the last chapter the reader never knows how the problems
that throw themselves upon a little group of naturalists and the sailors
that brought them to the island on which all these frightening events
occur, will be solved. NH
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