Bilbo Baggins, a Hobbit from the Shire, played by Martin Freeman

In honor of Tolkien Week, Peter Jackson has released a new trailer (below) for “The Hobbit: An Unexpected Journey,” delving more into Bilbo Baggins’ story and revealing first looks at several beasts of Middle-earth. The trailer, though action-packed, takes a less serious tone than the previous trailer, released some nine months ago, and certainly than “The Lord of the Rings” movie trilogy — a directorial decision that captures the lighter mood of “The Hobbit” compared to J. R. R. Tolkien’s later work; though we see Martin Freeman’s Bilbo Baggins bravely wielding Sting (his glowing sword) against a goblin, we also see him running barefoot through the Shire, map in hand, bellowing, “I’m going on an adventure!” Even Gollum, reprised beautifully by Andy Serkis‘ motion-capture performance, is more comedic (and even cute) than grotesque. The trailer is more narrative-focused, describing the dwarves’ mission to reclaim their homeland from the terrible dragon Smaug (Benedict Cumberbatch). Unfortunately, the trailer offers no glimpse of Smaug, but does give fans a sneak peek at several Middle-earth monsters, including stone giants, goblins and wargs (enormous wolves). The new trailer also introduces several characters new to the big screen, including Radagast the Brown (a wizard like Gandalf the Grey and Saruman the White), who warns that “a dark power has found a way back into the world.” Ian McKellen and Cate Blanchett return to play Gandalf and Galadriel, respectively, and the trailer reveals a shortened version of a scene revealed to a Hall H audience at Comic-Con International in which the elven queen asks the gray wizard why he chose Bilbo for this quest. “Why Bilbo Baggins? Perhaps it is because I’m afraid, and he gives me courage,” Gandalf answers. “The Hobbit: An Unexpected Journey” was originally intended to be the first of two parts, but Jackson revealed this summer he is planning for a third installment. The first film is due in theaters Dec. 14. In the meantime, fans can celebrate Tolkien Week leading up to Sept. 22 — Bilbo and Frodo Baggins’ birthday. Sept. 21 marks the 75th anniversary of “The Hobbit.” And click through the gallery above for a look at Bilbo’s adventuring company.