It's a highly controversial (read, politically incorrect) 1973 book about a wave of one million migrants landing in France and the resulting clash of cultures. Given the events in Europe it's looking downright prophetic right now.
More on it here: http://www.goodreads.com/book/show/11810...the_Saints
More on it here: http://www.goodreads.com/book/show/11810...the_Saints