As previously reported, Marshall Allman is set to come aboard season three of True Blood in the role of Tommy Mickens, Sam's brother.

How will this storyline be set up? According to William Keck of TV Guide Magazine, who was recently on the show's set, Sam will grow curious about his shape-shifting relatives and embark on a search beyond Bon Temps for them.

This is what we'll learn about them: Sam's dad was in jail when his mother learned she was knocked up, so she gave him up for adoption to an affluent family.

Says series star Sam Trammell: "[Sam] just wants to see what they're like and how bad they are... but he doesn't expect them to bleed back into his life, which is when the problems start."

Among other Sam-related spoilers/teasers for season three:

• Various flashbacks will reveal some naughty things Sam did after being abandoned by his adoptive parents. Trammell describes this as a "dark side" of his character.
• On episode six, we'll learn shocking details about Sam's birth father.
• Romance may bloom for Sam and yet another waitress, this one played by Lauren Bowles.

Matt Richenthal is the Editor in Chief of TV Fanatic. Follow him on Twitter and on Google+.