Claim: The Divergent Series: Allegiant is part of something.

Allegiant is a science fiction novel for young adults , 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 . The book is written from the perspective of both Beatrice -LRB- Tris -RRB- and Tobias -LRB- Four -RRB- . Following the revelations of the previous novel , they journey past the city 's boundaries to discover what lies beyond .   Allegiant was published simultaneously by Katherine Tegen Books and HarperCollins Children 's Books in the U.K. Four weeks earlier , a free electronic companion book to the trilogy titled The World of Divergent : The Path to Allegiant was released online . The novel is being adapted into a two part film , the first part of which was released on March 18 , 2016 .