While writer-director Sacha Polak’s new film may be dramatically overcrowded, “Silver Haze” is an occasionally effective motion picture and a perceptive piece that captures the rhythms of those who live with personal trauma.

An intense Vicky Knight is “Franky”, a young nurse from a rough working-class East London family. Bearing the scars from a childhood fire where she was burned in her father’s pub at the age of eight, Franky struggles with her personal demons. Seeking vengeance, as she is convinced the fire was started by her dad’s wife, Franky searches for closure.

Already burdened with such weighty personal pain, Franky is saddled with a broken family life. Her mother (Terriann Cousins) is an alcoholic, while her sister “Leah” (Knight’s real-life sister Charlotte) is stuck with an abusive partner. As Franky dreams of revenge against the woman who stole her father and nearly killed her as a child, she meets “Florence” (a terrific Esmé Creed-Miles), a suicidal young woman who was a patient at Franky’s hospital. Claiming early how she is not into girls and just wants to settle in with a normal guy, the two lost souls are drawn to one another; their affair appalling most of Franky’s family, further pushing her away.

Vicky Knight is quite good in the lead role. An actual burn victim (and former health care worker), the actress skillfully taps into the destructive force of one’s anger. Embracing the film’s semi-improvisational style (and drawing from her own experiences of surviving a similar fire in her real life childhood), Vicky Knight takes her character from frustration to anger to empathy. This is extremely good work from an actress in only her second film.

While Sacha Polak’s screenplay is quite astute in its examination of trauma, it is in the relationship between Franky and Florence (two tortured souls) where “Silver Haze” finds its deepest truths. For the first time, the two women are not afraid of their vulnerability, as they can be who they truly are around one another. Their relationship is, at times, angry and intense and gives fire to the film’s drama.

Polak’s style is comparable to that of Andrea Arnold in film’s such as “Fish Tank” and “American Honey”, in that she uses a semi-documentary approach to observe the lives of her characters. While this type of filmmaking has worked before, in today’s digital world it is too easy to shoot a picture in such a manner. Polak’s technique certainly has purpose, but “handheld” direction has passed its prime.

Sacha Polak and her lead actress crafted this picture based on workshopping recollections from Knight’s personal life, an exercise that pays off in the sharp focus on Franky and her sister. Adding in Florence’s grandmother Alice (Angela Bruce) and autistic brother (and following the grandmother’s dating issues) causes Polak’s work to meander and becomes an unnecessary side plot. When the film stays on Franky, her sister Leah, and Florence, the drama is at its most effective.