Which Harry Potter book was published simultaneously in 93 countries on 21 July 2007?

Harry Potter and the Deathly Hallows was published simultaneously in 93 countries on 21 July 2007.

It is the seventh and final novel in Rowling’s main Harry Potter series. The worldwide launch took place at 00:01 British Summer Time, creating coordinated midnight events in bookstores and libraries. The plot follows Harry, Ron, and Hermione as they search for Horcruxes and prepare for the final conflict with Voldemort.

The release was accompanied by unusually strict secrecy measures, including controlled distribution and instructions to retailers not to sell copies early. The book set first-day sales records in several markets and concluded the story of Harry’s years at Hogwarts, although later stage and screen projects returned to the wizarding world.