On this week's all-new episode of Untold, one of the topics that host Maria Menounos will investigate is heroin addiction in Hollywood and how it affected the life of actor Cory Monteith, who died at a young age as a result of his addiction and drug use.
The Glee star started using drugs at the young age of 13, was in rehab when he was 19-years-old and spent the last 12 years of his life in and out of sobriety.
In a candid interview, Cory's mother shared a sad revelation. "I had this feeling I really want to know him," she reveals in the above clip. "'Cause I'm not going to have him my entire life."
The late actor's girlfriend and fellow Glee co-star Lea Michele took to the stage at the Teen Choice Awards, where she and the entire Glee cast paid an emotional tribute to Cory.
"Whether you knew him personally or just as Finn Hudson," Lea said tearfully. "Cory reached out and he became a part of all our hearts and that's where he'll stay forever."
In Thursday's episode, Maria will be joined by addiction medicine specialist Dr. Drew Pinsky, who will explain why addicts have a hard time recovering from and staying off drugs. Other fallen stars who met a similar fate that will be featured on the episode include Philip Seymour Hoffman and Peaches Geldof.
Maria will also speak to actress Mackenzie Phillips, who opens up about her personal struggles with drugs, along with a former nurse who became a heroin addict after an emergency appendectomy.
Watch the above clip for a behind-the-scenes look at Cory's life and tune-in this Thursday to see more on this heartbreaking topic.
Tune-in to a brand new episode of Untold on Thursday at 8/7c on E!