Hillary Clinton's upcoming memoir is about her 2016 election loss to Donald Trump

What Happened will be the title of Hillary Clinton's upcoming memoir about losing the presidential election to Donald Trump. The book will be released in Canada on Sept. 12, 2017.

The 2016 Democratic candidate is promising unprecedented candour. In the introduction, Clinton writes that in the past, she's often felt she had to be careful in public, "like I was up on a wire without a net. Now I'm letting my guard down."

Publisher Simon & Schuster told the Associated Press that Clinton's book will be a highly personal work that also is a "cautionary tale" about Russian interference in last year's election and its threat to democracy.

Clinton has previously authored two memoirs. Hard Choices, which was published in 2014, chronicled her time serving as U.S.'s secretary of state  and 2003's Living History covered her early life through to her tenure in the White House as the First Lady. Her other books include the 2016 campaign guidebook Stronger Together, the coffee table book An Invitation to the White House, and the children's books Dear Socks, Dear Buddy: Kids' Letters to the First Pets and It Takes a Village.

— With files from CBC Books