EDITOR’S NOTE: As Comic-Con kicks off, we trust one fearless correspondent to wade deep into the first night’s geek shire: Comic Riffs contributor and Tall Tale Radio podcaster Tom Racine. From the “Iron Man 3” display to the towering “Hobbit” trolls, here’s his first dispatch from San Diego’s front lines of Nerddom Central.

— M.C.

FULL METAL SIGNAGE: With the billion-dollar-grossing “The Avengers” still in theaters, Disney/Marvel is ramping up for the third “Iron Man” film. Each time, star Robert Downey Jr. is a conquering hero of the Con. (Tom Racine/Special to The Washington Post)

On Wednesday, “Preview Night” lost its swag of wide-elbowed exclusivity, but replaced it with a certain shoulder-to-Spandexed-shoulder electricity. Even Thor doesn’t generate quite this much atmospheric, if not thermal, heat.

PARTY LIKE IT’S 1899: The perennial steampunk presence appears like (vintage) clockwork Wednesday at Comic-Con 2012. (Tom Racine/Special to The Washington Post)

At the Hasbro booth, a worker told me that Wednesday’s line was simply for getting a ticket that would allow you to come BACK to actually buy the pieces you want. In some ways, this is a pain, yet it saves time because once the tickets are gone, that day’s allowance of toys is also gone, so people don’t wait in line for hours to be told nothing is left. (Even if he did tell us that the line for the tickets was already too long and the toys were all gone TEN MINUTES after the doors opened.)

NEVER SAY DIE: Robert Kirkman’s comic-turned-smash AMC show rears its head early this year. (Tom Racine/Special to The Washington Post)

“The Expendables”sequel had a large presence, with a scrum of aging action stars coming to Hall H this week. Arnold Schwarzenegger, Sylvester Stallone, Dolph Lundgren, Jean Claude Van Damme — all those pumped-up deltoids and egos on the same stage. There was already a long line outside Hall H, which means many of those people have been camping there for a couple of days — a reminder that the die-hard fans are the Inexpendables in this commercial equation.

View Photo Gallery: Comic-Con 2012 in San Diego, Calif.

The cosplayers were not out in full force yet, mostly because the Preview Night is only open for three hours. Yet among the prematurely costumed, a convincing “Abraham Lincoln, Vampire Hunter” was the highlight.

We could have asked this no-nonsense Abe to help cut some of the zombie-paced hordes down to size Wednesday, but then again, something about the energy of a thousand-score Con-goers was exhilarating.

On Wednesday, the biggest thing to witness in advance — larger than even Hobbit statues — was the passion.