Actor Stellan Skarsgard single-handedly makes this sinister thriller more effective than you might expect. When the parents of 16 year-old Ruby Baker (Leelee Sobieski) and her 11 year-old brother Rhett (Trevor Morgan) are killed in a car crash, they're placed in the custody of their parents' best friends and former neighbors, Erin and Terry Glass (Diane Lane, Stellan Skarsgard). The Glasses' lavish, contemporary, gated glass house in Malibu offers a sun-drenched California distraction, complete with trendy clothes, state-of-the-art TV and video games. Squabbling Ruby and Rhett must share a bedroom, temporarily, but the estate lawyer (Bruce Dern) assures them that there's $4 million to insure their comfortable future. If they have a future, that is, since Ruby begins to suspect that the Glasses may not be the ideal guardians they seem to be. Erin, a doctor specializing in pain-management, is a moody drug addict, while Terry is heavily in debt to loan sharks. Working from Wesley Strick's hackneyed script, television director Daniel Sackheim ("Law and Order," "The X-Files") propels the creepy melodrama, unnecessarily underscoring the malevolence, aided by production designer Jon Gary Steele and cinematographer Alar Kivilo, who drenches the screen with cold, watery blue imagery. There's one almost-surreal, amusing moment when a group of Valley teens emerge from a showing of "Prom Nightmare," and one notes, "That actress was no Meryl Streep." "Who's Meryl Streep?" another asks. "She's like Katie Holmes to our parents" is the reply. On the Granger Movie Gauge of 1 to 10, "The Glass House" is a scary 6 - at least until the final transparent moments when it shatters into a formulaic teenage horror flick.