It was announced via the Fate/stay night Twitter account that the third Heaven’s Feel movie, Spring Song, will be returning to U.S. theaters once again on July 18 and July 20. The movie is returning via Fathom Events who also helped bring the movie to the U.S. for its first showing.
You can check out Fathom Events’ official website to search for tickets in your local area: Fate/stay night [Heaven’s Feel] III. spring song | Fathom Events
MyAnimeList describes the third movie as follows:
The Fifth Holy Grail War in Fuyuki City has reached a turning point in which the lives of all participants are threatened as the hidden enemy finally reveals itself. As Shirou Emiya, Rin Toosaka, and Illyasviel von Einzbern discover the true, corruptive nature of the shadow that has been rampaging throughout the city, they realize just how dire the situation is. In order to protect their beloved ones, the group must hold their own against the seemingly insurmountable enemy force—even if some of those foes were once their allies, or perhaps, something more intimate.
As the final act of this chaotic war commences, the ideals Shirou believes will soon be challenged by an excruciating dilemma: is it really possible to save a world where everything seems to have gone wrong?
You can check out the original Tweet below:
This war has become horribly twisted.
Watch the final chapter of the "Fate/stay night [Heaven's Feel] trilogy in theaters when it returns July 18 and 20!
🎟️ https://t.co/6h8JHcjQjP pic.twitter.com/48bJ4Yyqac— Fate/stay night USA (@FateStayNightUS) June 22, 2021
Source: Fate/stay night Twitter Account