Watch Batman: The Long Halloween (2021) HD Full Movie Free on solarmovie.do. Watch Batman: The Long Halloween (2021) online free. Atrocious serial killings on holidays in Gotham City send The World's Greatest Detective into action...Atrocious serial killings on holidays in Gotham City send The World's Greatest Detective into action - confronting both organized crime and a unified front of classic DC Super-Villains - while attempting to stop the mysterious murderer.