There were twists and turns that no one predicted. Who would have bet that “Indiana Jones and the Kingdom of the Crystal Skull” would not have the summer’s biggest opening, or that “The Dark Knight” and “Iron Man” would outgross it? Bottom line: Success at the box office can be determined by a confluence of mysterious factors.

The Christian Bale and Heath Ledger superhero picture has now accumulated $441.5 million at the US box office, surpassing “Shrek 2” as the third highest domestic grosser of all time. It’s expected to beat “Star Wars’ ” $461 million total in the next week before finally settling at No. 2, behind “Titanic.”

The Sony comedy nabbed a record-breaking $12.5 million at the US box office. For the first time in its run, Warner’s “The Dark Knight” came in No. 3 for the day, behind “Pineapple Express” and “Sisterhood of the Travelling Pants.”

“Dark Knight” has every chance of nearing or crossing US$500 million in the United States, making it the second highest grossing title of all time after “Titanic,” which accumulated US$600.8 million in ticket sales at the US domestic box office.

Privately, Universal and most box office observers had expected “Tomb of the Dragon Emperor” to beat “Dark Knight” at the domestic box office, but the Batman sequel’s resilience and muscle has continued to surprise.