Allegiant is a science fiction novel for young adults,[1] written by the American author Veronica Roth and published by HarperCollins in October 2013. It completes the Divergent trilogy that Roth started with her debut novel Divergent in 2011.[1][3][4][5][6][7] The book is written from the perspective of both Beatrice (Tris) and Tobias (Four).[8] Following the revelations of the previous novel, they journey past the city's boundaries to discover what lies beyond.