Radical actions have equally radical consequences in Kelly Reichardt’s latest masterclass in gripping, under-the-radar filmmaking.

With just five features to her name over the course of a 20-year career, Reichardt has developed into a darling of indie cinema with a unique perspective on the American landscape (mostly Oregon) and the characters who exist on its periphery.

In each of her films, from the little seen debut River Of Grass (1994), through to Old Joy (2006), Wendy And Lucy (2008) and her period western Meek’s Cutoff (2010), Reichardt fixates on characters who are emotionally or physically lost and in pursuit of a better world.

These themes remain present in Night Moves, in which eco-activists Josh (Jesse Eisenberg), Dena (Dakota Fanning) and Harmon (Peter Sarsgaard), exasperated by the well-meaning rhetoric of their fellow environmentalists, decide to take direct action by buying a boat (called Night Moves), stuffing it full of ammonium nitrate fertiliser and rigging it as a floating bomb to blow up a hydroelectric dam.

This, Josh declares, will finally awaken people to the environmental damage being wrought upon the world. However, an unforeseen consequence of their actions has Dostoevskian ramifications on Josh and Dena especially as guilt, paranoia and fear begin to overwhelm them.

Although this is doubtless Reichardt’s most political film, she is careful to chart a neutral course down what is a challenging river. The director also cleverly edits as if from Josh’s perspective and returns to the character as he reacts to events around him.

In an early scene, an eco-movie is being projected for a group of well-meaning types. Josh is present, although tellingly stood on the sidelines, and looks on with increasing disdain at the rhetoric of his fellow environmentalists, to the extent that the film cuts away mid-speech to reflect the disinterested contempt of its leading character.

Josh is a man of few words and has a high-minded intensity that cloaks the restless anxiety etched in his eyes. His lofty words have clearly won over the right-on Dena, a rebellious child of wealthy parents whom Josh is using to bankroll the operation; while the military-trained Harmon leads the sort of off-the-grid lifestyle Josh clearly aspires to.

Although angry at the injustice that allows salmon to be killed by the dam “just so you can run your iPod all your life”, Josh’s actions betray his eco-sentiment. A dead, pregnant doe he discovers on the side of the road is treated as an inconvenience, while extraneous parts of the boat are ripped out and discarded at a landfill site. Dena, too, identities the species of a bird through its song at one point, although Josh doesn’t even respond; lost in the statement he perceives his actions will make.

Reichardt masterfully turns the screw and invokes a growing sense of stifling suspense in the film’s first half and the central dam-busting sequence has a near-wordless tension reminiscent of the celebrated robbery sequence from Jules Dassin’s Rififi (1955).

Once the dam bursts, the nail-biting pressure gives way to an increasingly paranoid thriller that becomes more suspicious and jittery (soundtracked to perfection by Jeff Grace’s John Carpenter-inflected score) as the film largely jettisons Harmon and Dena and fixes its gaze almost completely on Josh. Never one for showy roles, Eisenberg dials everything down still further to present us with a character lost in his own despair and guilt.

Sarsgaard is subtly effective as the hardcore Harmon, while Fanning impresses as Dena, who is involved in one of the film’s most suspense-fulled scenes as she uses her wiles to try to convince James LeGros’ shop owner to sell her the fertiliser.

Night Moves quietly and assuredly sucks the room out of the air until what you are left with is a vacuum of tension that doesn’t let you breathe until its final shot.