With apologies to Ron Howard and the rest of the creative team behind "The Da Vinci Code," the hottest mystery of the summer movie season has nothing to do with albino assassins or secret Christian codices. Not even close.

It has everything to do with Tom Hanks' hair. I mean, what's going on there? Did he straighten it? Did he color it? Is he going for some of the John Travolta-junkie hit-man look? Celebrity-addled minds want to know.

If we follow the suggestion of "The Da Vinci Code" tag line to "seek the truth" and shine the hard, hot light of inquiry on the summer movie schedule, other intriguing uncertainties will resolve into clarity.

For starters, we'll find out who's the bigger comedy draw: Vince Vaughn in "The Break-Up" or Will Ferrell in "Talladega Nights: The Ballad of Ricky Bobby."

We'll see if America is ready to face its 9/11 demons in Oliver Stone's "World Trade Center."

And we'll cross our collective fingers as obscure soap actor Brandon Routh takes over as the Man of Steel in "Superman Returns."

Most important of all, the 2006 summer movie season will determine whether Hollywood is on the rebound after posting its biggest dip in overall ticket sales since 1985.

So look into the light, movie fans. The truth is out there.

Not all summer movies are created equal. Here are five of the biggest, the ones that realign the summer movie constellation, ranked in no particular order.

"The Da Vinci Code": Call it the anti-"Passion of the Christ." Readers worldwide have been scandalized and thrilled by Dan Brown's 40-million-copy-selling, Vatican-censured potboiler, making this perhaps the summer's most anticipated film. But page-to-screen projects can be tricky — as "Da Vinci" star Tom Hanks knows firsthand from "The Bonfire of the Vanities" debacle. As Holy Grail-hunting symbology expert Robert Langdon, Hanks reunites with "Apollo 13" director Ron Howard. Opens tonight.

"Superman Returns": After innumerable false starts (including an aborted "Superman" project headed by "Clerks" director Kevin Smith), the long-grounded franchise finally takes flight on the shoulders of filmmaker Bryan Singer, who wanted the Man of Steel so bad that he bailed on his beloved "X-Men." Wisely, the filmmakers have set the movie — pitting hunky unknown Brandon Routh against Kevin Spacey's Lex Luthor — after the events of "Superman II," banishing later, lesser sequels to their own phantasmic mirror-prison in space. Chris Lee, director of the University of Hawai'i's Academy for Creative Media, is one of the film's three executive producers. Opens June 30.

"Cars": Does Pixar still have the magic? The animation studio's first feature in two years (its last was 2004's "The Incredibles") taps directly into the NASCAR craze, telling the story of a waylaid rookie stock car (voiced by Owen Wilson) who discovers the meaning of friendship and sacrifice while doing community service in the autos-only desert hamlet of Radiator Springs. Paul Newman, Cheech Marin, Bonnie Hunt and others provide voices. Opens June 9.

"Pirates of the Caribbean: Dead Man's Chest": As devastated as we all were when it was announced that Keith Richards would not make a cameo as Jack Sparrow's dad, it's hard to imagine that this sequel to the 2003 blockbuster — with its star cast (Johnny Depp, Orlando Bloom, Keira Knightley) and director Gore Verbinski returning — will be anything less than a madcap people-pleaser. This time, Sparrow (Depp) is on the run from angry creditor Davy Jones and his army of sea-phantoms, to whom he owes his soul. Opens July 7.

"World Trade Center": One never knows precisely what to expect from Oliver Stone. Will he play the provocateur of old, the grousing revisionist and antiestablishment skeptic? Or will he follow recent form and settle for mere misguided sensationalism? (See "Alexander.") Considering the explosive subject matter, this is touchy either way. If Stone has a conciliatory bone in his body, this is the movie that will reveal it. Based on true events, Nicolas Cage plays a port-authority officer trapped in the WTC wreckage. Maria Bello and Maggie Gyllenhaal lead the supporting cast. Opens Aug. 9.