Simultaneously frank and elegiac, Keep the Lights On is an extraordinarily potent romantic drama that's not about addiction but rather about what it's like to love a drug addict. That vital distinction makes sense, given that documentary filmmaker Erik (Thure Lindhart) meets aspiring lawyer Paul (Zachary Booth) while looking for a quick fling that ends up lasting close to a decade. The story of their affair is not one of doom foretold, but of a relationship that waxes and wanes because it's built on an unconventional, inherently unstable foundation.
That instability gives Keep the Lights On its erotic intensity as well as its heartrending pathos: this is a love that could end at any time. Writer/director Ira Sachs (Married Life, Forty Shades of Blue), who based the film partly on his own life, subsequently acknowledges both the perils and the seductive qualities to Paul's increased drug abuse. For example, a scene where Paul languidly exhales smoke from a crack pipe is not a sign of an impending overdose, nor is it luridly pretty. Instead, it's a moment in time gracefully captured by Sachs without judgment.
The movie's measured fly-on-the-wall observational style makes Keep the Lights On the best film to date by native Memphis filmmaker Sachs. Paul and Erik's rocky relationship, defined by Paul's abrupt disappearances and Erik's harried refusal to believe the worst about his partner, is deeply sympathetic. As a couple, their shared life is defined by small gestures, whether deferred stares or pregnant pauses.
Paul and Erik may be fictional characters, but they exhibit a remarkable interior life under Sachs' rapt gaze. Lindhart and Booth have genuine chemistry, and Sachs honors that by giving Erik and Paul enough room to develop, separately and together. They're such convincing protagonists we can imagine their existence long after their relationship ends, and with it the film.