Obsession. It can make us miss the joy available to us because we focus so much on what we do not have. In Notes on a Scandal, obsession shapes the lives of two women.

Sheba (Cate Blanchett) is a new teacher. She has spent the last several years caring for her family and feels the need to find something new in her life. It's not that there is anything wrong with what she has, she just wants more.

Barbara (Judi Dench) has been teaching a long time. She is burnt out and cynical--at least that is the first impression we get. Later, we discover someone much darker. She is alone in the world except for her fantasies.

Sheba falls into a sexual relationship with one of her students. The student seems to be the main initiator of this relationship, but that in no way absolves Sheba from responsibility. In fact, Sheba cannot bring herself to put an end to what is inevitably a disastrous liaison. She is obsessed with the sexual vitality she experiences with the boy.

Barbara discovers the affair and uses it as blackmail to have a relationship with Sheba. There is no overt sexual component to this, but we sense a bit of repressed sexual desire on Barbara's part. As she writes in her journal about Sheba, there is a kind of yearning that she seems to think is reciprocated, when in fact, it is all in her somewhat demented mind.

These obsessions create turmoil in Sheba's life and family. She is both the focus of obsession and the origin of obsession. The cross currents of these obsessions are bound to lead to destruction not only of those involved but all those around them.

There are differences between the obsessions. Sheba is certainly wrong to become involved with a student. Hers is not a predatory obsession, but a failure to maintain proper boundaries. Hers is a serious breach of responsibility, and there is a price to be paid for that breach.

Barbara, however, is pathological in her obsession. She writes in her journal about this blossoming friendship in glowing terms and even puts gold stars in to mark special days. When we hear the things she writes and compare them to the events we see on screen, we are aware that her reality is not the same as the one we are experiencing. Barbara, we discover, is a predator. She believes that there is love between herself and those on whom she centers her attention. Her obsession carries a different destructive force, a force that brings the brunt of the pain on others rather than to herself.

This film is carried by two very strong performances by Dench and Blanchett. Dench is especially noteworthy, playing this malevolent woman with a depth beyond almost any woman's role this year. Both performances take us into the world of their obsessions--worlds that lose all perspective of what is true and valuable.

That is the problem with obsessions; they blind us to the good that we have for that which we long for. In the story that plays out in Notes on a Scandal, these obsessions never bring the joy that is hoped for. Rather they bring far more pain than those who obsess ever imagine.