"Mandela: Long Walk to Freedom" is one of those obsessively linear, respectful biopics that begins toward the beginning and ends roughly at the end.

It's a far less interesting form of filmmaking than the alternative, as personified by, say, Clint Eastwood's "Invictus," in which a snippet of the subject's life is used to illuminate the whole.

But this "Mandela" profits from Idris Elba's remarkable take on the central figure, which carries every scene.

The actor captures Mandela's mannerisms, the deceptively soft-spoken vocal cadence and other characteristic traits, but the work transcends imitation.

Fundamentally, Mandela's life offers a sterling study of the power and importance of forgiveness, that crucially important step in healing past wounds and carving a better future.

Elba taps into this key strain, subtly transitioning over the course of Mandela's incarceration from the younger man who accepted violence as a tactic to the elder statesman who pushed his people to convey their anger at the ballot box, not on the streets. It's greatness rendered palpably real.