“Watchmen” is perhaps the holy grail of geek movie adaptations. The book has been called “unfilmable” by more than one pundit, but director Zack Snyder (“300”) has apparently succeeded in adapting the long-gestating graphic novel.

The comic miniseries-turned-graphic novel centers on a group of superheroes living in an alternate-universe. Richard Nixon has been president for 15 years, the U.S. won Vietnam (with the help of a superhero), and the Cold War is ready to come to a head, as rumors of a nuclear attack from the Soviet Union has left the country a nervous wreck.

Costumed heroes, outlawed by the 1977 Keene Act, either retired, registered and worked for the government, or, in one case, went rogue.

For those unfamiliar with this classic graphic tale, here’s a guide to the characters of “Watchmen”:

Silk Spectre

True identity: Laurie (Jupiter) Juspeczyk.

Played by: Malin Ackerman (“The Heartbreak Kid”).

Power/gimmick: Somewhat of a sex symbol among superheroes. As much celebrity as crime fighter.

Key relationship: Romantically involved with Jon Osterman, who was rendered emotionless when he was turned into Dr. Manhattan in an accident in the 1950s.; the daughter of the original Silk Spectre, Sally Jupiter.

Trivia: Her mother pushed her into becoming a superhero, leading her to resent both her mother and the superhero lifestyle. She harbored bad feelings for The Comedian over his treatment of her mother.

Rorschach

True identity: Walter Kovacs.

Played by: Jackie Earle Haley (“Little Children”).

Power/gimmick: Intimidation, ruthlessness toward criminals, gruffness towardeveryone else. Wears a mask designed to look like a Rorschach blot.

Key relationship: Ex-partners with the Nite Owl. Left embittered when the Keene Act forced most remaining heroes to register with the government or retiring.

Trivia: One of two remaining active heroes not registered with the government; is wanted for murder.

Nite Owl

True identity: Dan Dreiberg.

Played by: Patrick Wilson (“Hard Candy”).

Power/gimmick: Wears an owl costume with a Batman-like look and gadgets, including a flying “Owlship.”

Key relationship: Maintains a friendly relationship with the original Nite Owl, Hollis Mason. Still pines for the hero gear he spurned.

Trivia: Mason wrote a tell-all book about his time under the cloak that painted several of the heroes in a bad light.

The Comedian

True identity: Edward Blake.

Played by: Jeffrey Dean Morgan (TV’s “Grey’s Anatomy”).

Power/gimmick: Young, cocky, brutal anti-hero turned patriotic enforcer.

Key relationship: His murder sets the plot in motion; he was kicked out of the superhero group The Minutement when he attacked and tried to rape Sally Jupiter in the 1940s.

Trivia: Mostly reviled by the other heroes, he is one of two government-sponsored heroes.

Ozymandias

True identity: Adrian Veidt.

Played by: Matthew Goode (“Brideshead Revisited”).

Power/gimmick: “The smartest man in the world,” Veidt gave up his family fortune to study his idol, Alexander the Great. He later became a costumed adventurer.

Key relationship: Has an affinity his genetically-engineered lynx Bubastis.

Trivia: Ozymandias rebuilt his fortune by marketing his hero persona and building a global commercial empire. He has no superhuman powers, but claims to be able to catch a bullet.

Dr. Manhattan

True identity: Jon Osterman.

Played by: Billy Crudup (“Mission: Impossible III”).

Power/gimmick: Transformed into the metaphysical blue-skinned superbeing after an accident that disintegrated him. The same accident granted him god-like powers but left him cold to human emotion. The only hero with actual superhuman powers.

Key relationship: Romantically linked to Laurie Juspeczyk.

Trivia: One of two government-sponsored heroes. His existence (and great powers) have heightened tensions between the Soviet Union and the U.S.