Know your Sauron from your Saruman? Ever mix up Gimli and Gollum, or an Orc and an Uruk-hai? Read this cheat sheet before you see The Lord of the Rings: The Two Towers, which opens Wednesday, kicking off with midnight showings.

The new film picks up where The Fellowship of the Ring ended: Frodo and his loyal friend Sam are on their perilous way to the scary city of Mordor, to toss the powerful, corrupting One Ring into the Mount of Doom volcano.

The fellowship that was formed to help them destroy the ring is in shambles.

Their Hobbit pals Merry and Pippin have been kidnapped by an army of Orcs (ugly bad guys), the wizard Gandalf has plunged into a canyon while fighting a demon, and the human Boromir has been slain by enemy soldiers. Good guys Aragorn, Gimli and Legolas are trying to find the Orcs who captured Pippin and Merry.

And on the dark side, Saruman the White is forming an army of Orcs to eradicate any good in Middle-Earth.

GOOD GUYS

Gandalf, wizard (Ian McKellan)

A good-humored and extremely powerful wizard, Gandalf leads the Hobbits through the Mines of Moria, only to fall victim to his darkest fear, the Balrog, a demon of flame. While it seems his life may be over, wizards are always full of mystery and surprise.

Aragorn, human (Viggo Mortensen)

Heir to the throne of Gondor, a city of men. Known to many folks as Strider, he has wandered Middle-Earth as a vagabond for years, ashamed of his royal ancestor, Isildur, who died by the temptation of the ring. Now, Aragorn has come out of hiding to help Frodo destroy the ring and all evil on Middle-Earth.

Frodo Baggins, hobbit (Elijah Wood)

Adventure-seeking Frodo is entrusted with the ring by his caretaker, Bilbo Baggins. Having the power to withstand the temptation of the ring longer than others, he leaves the pleasant village of the Shire and sets out to destroy the evil ring by casting it in the Mount of Doom.

Legolas, elf (Orlando Bloom)

Lethal with bow and arrow, Legolas can also sense Orcs from miles away. He puts aside his disdain for dwarfs and starts a friendship with Gimli (they even count who can kill more men).

Arwen, elf (Liv Tyler)

The elf princess can't stop loving Aragorn and is willing to give up her immortality so she can spend the rest of her life with him. Saved Frodo after he was stabbed by the Ringwraiths in "The Fellowship of the Ring."

BAD GUYS

Saruman, wizard (Christopher Lee)

Once a good wizard, Saruman craves power and is lured by the evil of Sauron, the most evil and powerful of them all, who is not a physical being. His spirit survives through the One Ring, which has been lost for centuries after his hand was cut off by Isildur of Gondor.

Saruman builds his own army of evil Uruk-hai creatures by burning trees of Isengard into an industrial furnace.

Orcs and Uruk-hai, ghoulish soldiers (played by stunt artists and created through special effects)

The Orcs are savage cannibals bred out of both elves and men. Slaves of Sauron, they attack only in darkness because the sun weakens them. Uruk-hai are manifestations of Saruman that were bred in Isengard and can withstand the light.

Grima Wormtongue, human (Brad Dourif)

The counselor to well-intended King Theoden is a snaky double agent for Saruman. He brainwashes Theoden to banish his own nephew (Eomer) from the city. Wormtongue is also in love with Eomer's stunning sister Eowyn --who, by the way, prefers Aragorn --and torments her as well.

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