The movie Serenity takes place a few months after the last episode of Firefly, the TV series it's based on. Firefly ended with one of its ensemble, the glamorous "Companion" Inara, planning to leave the ship where they made their home; in Serenity, she's already long gone. And so is Shepherd Book, who moved aboard in Firefly's pilot episode. When and how exactly did they leave? What impact did that have on Mal, the hero of the show? The movie doesn't have time to get into all that.

But that's what novelizations and comic book adaptations are made for.

Dark Horse's three-issue Serenity comic, subtitled "Those Left Behind," reads like a lost episode of the show. Another lost episode, anyway, since the Firefly DVD already included three complete episodes that never aired on TV.

The action kicks off with Shepherd Book giving a sermon to a church full of rural homesteaders — while Mal and the gang rob the town's vault not far away. But another gang shows up and robs them of their loot. The crew grab Badger, a fixer they've dealt with before and whom they suspect of tipping off the goons that robbed them. But Badger claims to know nothing about it, and he offers them a much-needed job to replace it. There's a hoard of cash stashed away in a ship in the wreckage of a huge space-battle from the war, and if they agree to give him a cut they can go collect it.

In the meantime, a pair of Firefly's sinister three piece suit-wearing "blue hand" men, still hunting Serenity passenger River Tam, pay a visit to a man with a score to settle: Dobson, the bounty hunter Mal shot during the show's pilot episode. Dobson has the contacts and obsessive drive to track Serenity down; the blue-hand men can get him government approval. And Dobson knows just where Serenity is heading next.

Will Conrad's art and Laura Martin's colors are consistently impressive, with plenty of detail and nice attention to lighting and shade. Characterization is generally good, if sometimes a bit wooden.

Characterization is a worse problem in the script. Sure, the story was drafted by Serenity creator Joss Whedon himself, but the actual dialog often doesn't ring true. Presumably Whedon, a terrific comics writer, was too busy with the movie and with Marvel's Astonishing X-Men to script it himself; whatever the reason, it shows. The lingo is about right, but there's none of the snap and subtlety of the show or the movie. And some actions are just jarringly out of character. Maybe the scene where would-be pacifist Shepherd Book punches the hell out of smart-mouth Mal made sense when Whedon conceived it, but as written on the page it seems to come out of nowhere.

"Those Left Behind" is a fun curiosity if you're a Firefly loyalist, but it doesn't add much to the story; it certainly doesn't provide anything essential to those picking up the show's story in the film, and the too-frequent mischaracterizations leave it feeling like — well, like an adaptation. Don't let Whedon's name on the cover fool you.