Director David Cronenberg reunites with charismatic leading man Viggo Mortensen to explore the dark secrets of a Russian crime family in his intense and bloodthirsty new thriller, Eastern Promises.

Opening with a gory sequence in a barbershop that gives new meaning to giving someone a close shave, the film pulls no punches in its depiction of the brutality in London's underworld, as imagined by screenwriter Steven Knight (Dirty Pretty Things).

Cronenberg is well suited to brutality and bloodshed, having traversed similar territory in A History Of Violence.

Here, he evokes a seamy vision of the capital, far removed from the picture postcard images of the Thames and London Eye; a rat run of grey concrete and eerie alleyways where bodies can be thrown into the river and dragged under by the strong currents.

Caring midwife Anna Khitrova (Naomi Watts) inadvertently strays into the middle of a gang war when she becomes emotionally attached to a badly injured teenage girl and her newborn baby.

When the young mother dies, Anna steals her diary and begins to translate the Cyrillic text with the help of her mother Helen (Sinead Cusack) and belligerent, Russian-born uncle Stepan (Jerzy Skolimowski).

The hand-written confessional reveals unspeakable treachery in a clan ruled by Semyon (Mueller-Stahl), his son Kirill (Vincent Cassel) and gruff chauffeur Nikolai (Viggo Mortensen); terrible deeds which Semyon will do anything to keep hidden.

The patriarch makes thinly veiled threats to Anna, determined to keep the past buried, and then Stepan vanishes without trace after an altercation with Nikolai.

Eastern Promises is a tour de force of robust, assured direction and powerful performances.

Violence is used sparingly, but to devastating effect, like the bruising fight in a bathhouse between a completely naked Mortensen and two knife-wielding assailants that ends with the tiled floor and walls spattered in blood.

Watts taps into the vulnerability and loneliness of her caregiver, whose interest in the orphaned baby stems from a doomed interracial relationship in the past.

Her performance is in stark contrast to Mortensen's brooding portrayal of a brute, who casually stubs out cigarettes on his tongue.

The relationship between Mortensen's protector and Cassel's prodigal son veers along an unexpected tangent later in the film, leaving several questions unanswered.

As tensions escalate and members of the criminal fraternity turn against one another, we're left in no doubt that when the film ends, the dark night of murder and retribution has only just begun.