Melissa McCarthy has been unfiltered and brash (The Heat), she's been socially maladroit (Bridesmaids), and God knows she's been funny (Spy), but she's never brought all of those things to bear in one performance.

She does that in Can You Ever Forgive Me?, a movie that plays to McCarthy's many strengths and that also finds the actress surrounded by the trappings of a prestige part — a biographical role about a complicated person who lived a colorful life — that could net her her second Oscar nomination, after her Bridesmaids breakout.

McCarthy plays Lee Israel, a biographer and journalist who wrote books and magazine articles about Katharine Hepburn, Tallulah Bankhead, Estée Lauder, and other famous people. She was good enough that colleagues overlooked how abrasive she could be, but when book sales slowed and work dried up, people stopped overlooking.

So Israel, low on funds and facing eviction from her Manhattan apartment, took to selling letters and mementos she'd collected from her famous subjects, and when the supply of legitimate letters was exhausted, she started forging them.

These crimes, though, are just a backdrop to an offbeat character study that places great emphasis on McCarthy's ability to humanize her irascible character — an abrasive, heavy-drinking recluse. McCarthy rises to the challenge, suggesting Israel was a woman who didn't know how to let people into her life and who finally gave up trying.

And, yes, McCarthy makes us laugh along the way.

So is this really new ground for the bankable comedy star?

"It never occurs to me to think about whether this comedy or that is drama. I'm not a big one to categorize things. Even when I'm playing a character who is particularly bombastic or over the top, I'm really thinking about how to ground all of that behavior in some kind of human truth. There's a reason for all of it. And that's what I'm trying to find. If someone is aggressive, for instance, maybe that's some kind of defense mechanism. Maybe there's something there they are trying to conceal or protect," she said.

Before she gets to the end of the sentence, she realizes she's talking about Israel, who by the time we meet her in Can You Ever Forgive Me? has burned many bridges, professional and personal. At the story's outset, she's down to her last companion, a cat.

"I think it's true that Lee is certainly different from anyone that I've played before. I think she's way more flawed, and that's a challenge. But it's where the joy in acting comes from. When you're playing that square peg in the round role, it's just more fun. And with Lee, wow, she was definitely not your average person. She was so … inward. She's shut so many people out of her life. It's easier for her to make somebody go away than it is to admit somebody into her world," McCarthy said. "The pacing of the character was different. The way she navigated the world was different, but for me, the process of getting inside Lee was really the same."

What McCarthy found there was a kind of heedless candor and fearlessness that — delivered in the right pitch — could produce empathy and even laughter.

"I think, especially today, there is great emphasis on how other people view us. And that's the thing about Lee. She did not care one bit," McCarthy said.

McCarthy had Israel's memoir to draw from but admitted  she initially had a hard time finding a route into her subject's walled-off psychological interior.

She talked to Israel's friends and studied photographs of the author.

"That really helped me, in this case. You're talking about a woman who had been successful and who had fallen on hard times. So we thought about clothes that were nice and expensive, but also old and well-worn. And maybe not the height of fashion,"  McCarthy said. She spent a lot of time thinking about the books Israel read, the music she listened  to — many of those tunes are featured on the soundtrack.

"Finding Lee was like a game of Tetris, the right aggregation of things, and it was the sum of all the pieces that finally formed a coherent whole," she said, praising director Marielle Heller (Diary of a Teenage Girl) and costar Richard E. Grant.

Grant plays a fellow barfly (and another rejected member of the Manhattan literary scene, for different reasons) who befriends Israel, rather insistently, pushing past her defenses, becoming her friend and partner in crime. Crimes, by the way, that are eventually uncovered and prosecuted. McCarthy said part of what attracted her to the role, and to Lee, was the unique nature of the fraud. It drew on Israel's skills — she understood and practiced the craft/art of writing well enough to convincingly imitate authors like Dorothy Parker and Noël Coward. She needed to know their personal histories and also their prose style, and she needed to be able to imitate it. This she did, taking a measure of pride in putting one over on the literary world that had cast her out.

On that score, McCarthy found empathizing with Israel easy.

"I'm the least qualified person in the world to pass judgment on Lee. Look what I do for a living. I pretend to be other people. I pretended to be her."