Defying speculation that moviegoers had become frustrated with Hollywood’s product, 20th Century Fox’s “Fantastic Four,” the latest adaptation from the Marvel Comics library, opened with $56 million from 3,602 theaters. “Four’s” bow, the third biggest opening of the year after “Star Wars: Episode III – Revenge of the Sith” and “War of the Worlds,” was a come-from-behind victory for Fox after the movie was forced to move off its original Fourth of July release date and was panned by most critics. Elsewhere at the box office this weekend, Paramount and DreamWorks’ “War of the Worlds” had a formidable 52% drop in its second weekend, netting $31.3 million over the frame and lifting the total on the Steven Spielberg-Tom Cruise sci-fi adventure to $165.8 million in its first 12 days. “Batman Begins,” down 35% in its fourth weekend, grossed $10.2 million to lift its total to $172.1 million. “Batman” edged just past the $10.1 million debut for Disney’s horror movie “Dark Water,” which opened Friday at 2,657 theaters. Rounding out the top five was Fox’s “Mr. and Mrs. Smith,” which took in $7.9 million in its fifth frame, bringing its total to $158.7 million. Playing its fifth weekend, the Brad Pitt-Angelina Jolie starrer was off just 26% from the Independence Day performance.