Allegiant is a science fiction novel for young adults, written by the American author Veronica Roth and published by HarperCollins in October 2013.

[1] Four weeks earlier, a free electronic companion book to the trilogy titled The World of Divergent: The Path to Allegiant was released online.

A future dystopian Chicago has a society that defines its citizens by strict conformity to their social and personality-related affiliations with five different factions.

Tris is invited to a meeting with the Allegiant, whose leaders, Cara and Johanna Reyes, plan to usurp Evelyn and send envoys outside the city.

Tris is selected for the expedition, alongside Tobias, Cara, Christina, Peter Hayes, Uriah Pedrad, and Tori Wu.

David explains that Chicago is walled off from the outside world in an experiment sanctioned by the US government to produce genetically-purer (GP) "Divergents" from the genetically-damaged (GD) population, the result of a failed attempt to correct human genes that led to the "Purity War."

Tris is appointed a council member and realizes that the Bureau supplied Erudite with the simulation serums that controlled Dauntless in the invasion of Abnegation.

To celebrate Choosing Day, he, Christina, Caleb, Zeke, Shauna, Cara, and Matthew ride a zip line from the Hancock Building, where Tobias scatters Tris's ashes and finally accepts her sacrifice.

On July 18, 2013 at the San Diego Comic-Con panel for the film Divergent, Roth revealed that Allegiant is from the points of view of both Tris and Four.

"[10] The World of Divergent: The Path to Allegiant is a promotional electronic book by Roth that was released free of charge by HarperCollins on September 24, 2013.

[1] Roth continues to write related fiction, and The Path to Allegiant is a companion book to the entire Divergent universe[1] in many respects.

[17][18] In a review for Entertainment Weekly, Hillary Busis gave the novel B+ and wrote that "If you've already been sucked into Roth's world, you'll appreciate the book's twisty plot—which provides needed context for the series' prefabricated society—and its chastely torrid Tris/Tobias love scenes.

"[19] Publishers Weekly said in its review that "The alternating perspectives are bothersome at times, due to the similarity between Tris and Tobias's first-person narratives.