Tamil director Karthik Subbaraj’s Dorothy is set in 1995, in a village in Madurai where caste lines are thickly drawn, family honour is paramount and ascribed roles are rejected only on pain of death. The equation between Subbu and Karthi is forged in a cauldron of moustache-twirling masculinity.

Subbu (Sananth), the son of the moneylender Veeraiya (Muthukumar), and Karthi (Rishikanth) becomes fast friends despite differences in caste and social status. The foundation of the bond that begins in childhood and endures into adulthood includes a love for movies and Bruce Lee fandom.

Subbu is the martial arts expert as a child, saving Karthi from bullies. Boys never cry, Subbu keeps telling Karthi.

Nothing can possibly come between us, the buddies shrug. A mutual acquaintance laughs in response, having seen more of the world than these young men.

That something has the force of a tsunami, destroying all that Subbu and Karthi hold dear. In a typical film, that something is usually embodied by a woman, who can be relied on drive a wedge between best friends.

Dorothy (Keerthy Suresh) enters Subbu’s household as his sister-in-law and charms both Subbu and Karthi. Dorothy doesn’t only have an unusual name.

Amidst the seething machismo and normalised violence, Dorothy soothes like a balm on open wounds. Subbu gets particularly close to Dorothy, setting him on a dark and dangerous path. Karthi stands at a fork ahead on this road, waiting to set Subbu right.

As children, they watched Ramesh Sippy’s film Saagar in a hulking cinema hall. The same clip plays on a smaller television screen years later, when they are in different, and less cheerful, circumstances. Their worlds have shrunk and expanded in important ways.

Subbaraj’s tenth feature corrals Tamil cinema conventions for a story that has radical things to say about social conditioning, brutal punishment for rebellion and individual freedom. Dorothy plants deep roots in the Tamil soil even as it reaches for the sky.

To elaborate on Subbaraj’s extraordinary punts is to give the plot away. What can safely be said is that except for avoidable bloat and some overwrought patches of scripting, Dorothy is a terrific subversion of the conventional Tamil film romance. Within the framework of a crime thriller that has music by Ilaiyaraaja and striking compositions by cinematographer S Thirunavukarasu, Subbaraj shreds received wisdom with a brio that has to be seen to be believed.

The sequences up until the interval of the 146-minute movie are mesmerising, capturing the contours of a friendship that are twisted out of shape with Dorothy’s arrival. After Subbaraj has revealed his hand, there are some needlessly lengthy scenes revolving around Karthi’s ethical dilemma.

Unable to deal with Subbu as he thinks he should, Karthi dithers for far too long. Having spent a great deal of time with both characters in close quarters, the personality shifts take some getting used to.

Subbaraj recovers to deliver a finale that includes a first in Tamil cinema. A reworking of Ilaiyaraja’s 1994 hit Muthumani is the final note of subversiveness in a film that begins in one place and ends somewhere unexpected. Subbaraj’s messaging is idealistic but seductive too.

The gutsy and heartfelt performances by the lead actors go a long way in selling the dream. Sananth, the actor from the De Monte Colony films, and Rishikanth, most recently seen in Modha Rathribrilliantly portray the big swerves in Subbaraj’s screenplay.

There is solid backing too from the rest of the cast. Keerthy Suresh is compelling as the gentle and yet forceful woman who gives the film its title and the young heroes the belief than another world is possible.