Coming from the creator of the timeless "36 Chowringhee Lane", "15 Park Avenue" is a bit of a downer. Aparna Sen's superb sensitivities seem to peep out at us from all quarters in this attractively packaged, wonderfully performed film about coping with an illness.

The trouble is: nothing fits. Not the relationships, not the narrative pieces that keep slipping in and out of Sen's hands with infuriating impunity.

Of course, the director's heart is in the right place. Isn't it always! But what is she trying to say here? Is this the story of two sisters, one older wiser and normal, the other all messed up in the mind... or is it a treatise on the real and the unreal?

And the fact that Mithi (Konkona Sen Sharma) in a totally uncalled-for plot convulsion, is gang-raped by Bihari louts during a dangerous mission in Bihar, doesn't help the poor girl's psychological equilibrium... Or our understanding of how painful life could be for those who don't fit in.

Trouble is, Sen's screenplay is too troubled by the task of getting the mechanics of the illness right. We get shots of Konkona puking fashionably all over the bedroom carpet, shots of blood from her slashed wrist splattering the bed... or the blood on her thighs after she's raped in a hotel room and thrown out in the corridor.

The brutality of life and the beauty of the filmmaker's vision do not fuse in any combustive alliance.

We feel for Mithi and her vocally harassed sister. But the feelings aren't allowed to run deep enough. Instead of focusing on the troubled traumatic relationship between the two sisters and how the elder balances her siblings overpowering imbalances, Sen brings in a crowd of vacationers into the plot.

Soumitra Chatterjee and Waheeda Rehman as Shabana-Konkona's parents look bewildered, if not hammy. To make these two veterans act so badly requires a lot of deliberation and attention.

One wishes Sen had stressed the emotional crisis rather than the characters' ability to be funny, sassy and urbane all the time. Everyone except Konkona talks in trendy exclamations.

Maybe being psychologically maladjusted helps Konkona's character to connect with the disjointed words.

There's an excruciatingly flat sequence where a talkative woman visitor narrates her extra-sensory experiences with a god-man. This is to show how mental illnesses are camouflaged by blind faith even in elitist circles. All it actually shows is Sen's inability to handle crowds of characters in the same line of vision.

The director is always more comfortable in intimate moments. You wish there was more to share between the two sisters. The sheer pleasure of watching Shabana and Konkona at work is exquisite. Alas, like the impatient elder sister who wants the schizophrenic sister to give her space, the narrative is constantly gliding in and out of characters' lives.

One moment we get a vivid glimpse into the elder sister's scarily solitary battle to keep Mithi's illness in check. The next moment we're privy to Rahul Bose's introspection on the mentally ill girl's romantic liaison with him.

Rahul is, as usual, staunchly supportive. You wish a director of Sen's sensitivities would use him and the other talented male actors - Dhritiman Chatterjee, Soumitra Chatterjee - as more than mere supportive emblems in a ladies' tale.

As Rahul's suspicious and jealous wife, Shefali Shah delivers a surprisingly punch-packed performance. She has limited space. And she uses it to the optimum. Sometimes a little too much so, as though she knows Hemant Chaturvedi's steady and searching camera would soon move on to the two other distinguished actresses who form the core of the conflict.

That again is symptomatic of the narrative's problem with creating proportionate shadows in its architectural design. Light and shade fall in unmeasured patterns, often creating a strangely sterile kingdom of crisis in characters who are driven by demons that they don't comprehend.

Finally, what you're left with are the performances. Shabana towers over almost every aspect of the film. Watch her closely when she watches her screen-sister being whisked away to the asylum - a predictably sentimental moment lifted by Shabana's ability to ferret out the truth even in maudlin moments.

At times, specially when flirting mildly with the shrink (Dhritiman Chatterjee) Shabana gets skittish, as though she was purposely trying to lighten the burden of being.

But this diluted drama of psychological dissent is finally lifted by an absolutely brilliant, nearly flawless performance by Konkona. Whether it's her voice - conveying a collage of compulsive dilemma - or her fidgety reactions... Konkona plays her mentally ill character with just the right amounts of angst and detachment. A truly brave and bravura performance.

If only the narration was more supportive of these incredible actors... Sen builds the film to a contrived crescendo. The 'open' surreal ending is more ludicrous than lyrical.

And when Mithi's loved ones walk off after the girl's bizarre disappearance at the end, you feel a sense of betrayal that has nothing to do with the characters.