Every so often, a familiar actor comes along and delivers a performance of such intensity and emotional depth that it becomes not only a benchmark in that actor's filmology, but a sort of wake-up call to audiences. Such "Look what I can do!" roles can launch a serious career or serve as a lynchpin in the transition from supporting actor to leading player. Think Kevin Spacey in "The Usual Suspects" or Paul Giamatti in "Sideways."

It doesn't happen often. This fall it's happening twice.

As the villainous Charlie Prince in "3:10 to Yuma" and the mysterious, cockeyed Stranger in "30 Days of Night," Ben Foster has found a way to be both more intense than Russell Crowe and look like the guy having the most fun at a college party — in the span of a month.

After three "Ocean's" movies and a bevy of supporting roles, Casey Affleck, meanwhile, has come into his own as the mesmerized, sexually ambiguous killer in "The Assassination of Jesse James by the Coward Robert Ford" and in what really amounts to his first leading role, as the morally conflicted private investigator in "Gone Baby Gone."

"I knew it!" "Gone Baby Gone" director Ben Affleck [article id="1571440"]recently gushed[/article] of his younger brother. "My only regret is that there weren't more people who were against the idea of casting him [in 'Gone Baby Gone'] so I could have more fun saying, 'I told you so!' "

Then again, "I told you so" is perhaps the best response to the pair's sudden career ascension, given that maybe only their family members could have believed these performances were possible, despite a string of very strong supporting roles over the past decade.

While Foster wowed many with his work in flicks like "Alpha Dog" and found commercial success [article id="1523042"]playing the mutant Angel[/article] in "X-Men: The Last Stand," for instance, never has critical buzz and wide appeal simultaneously crested for him as it has after "3:10 to Yuma."

"Every day [on the set of 'Yuma'], there was a moment where [I said], 'What am I doing here?' " he told MTV News. "It's that Talking Heads song: 'This is not my beautiful house. How did I get here?' "

It's easy to say that Foster, like Affleck, got there with some combination of luck and talent, but both pointed more toward collaboration as a mitigating factor.

"I worked with Ben [Affleck] for months leading up to the shooting, talking about the character over and over and over," Casey Affleck said of his role in "Gone Baby Gone." "Some of my ideas became written into the script, and some of what was written in the script became, sort of, part of my own conception of the character."

"It was collective," Foster echoed on his work in "Yuma."

Luck, talent and a willingness to learn — it's a combination that has colleagues singing their praises.

"He's great. He is terrific," Ben Affleck said of Casey. "It's my real hope that people will recognize that and say, 'Hey, this is a great job,' and that it will open up even more opportunities for him."

"He completely inhabits the character," producer Sam Raimi said of Foster's "30 Days of Night" performance. "Ben lives within this guy and really brings [multiple] dimensions to the screen in his performance. He's really intense, believable and doesn't put on affectations. He just is the character."

Now that they've both established popular and critical cred, where do these actors go from here?

"Can I carry a movie?" Foster asked. "Does that interest you?"

Anyone want to tell either of them "No"?

Check out everything we've got on "3:10 to Yuma," "30 Days of Night," "The Assassination of Jesse James by the Coward Robert Ford" and "Gone Baby Gone."

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