Rami Malek said he expects to grieve when his "Mr. Robot" psychological drama ends with its fourth season this year. USA Network announced in August that the show would not return for Season 5. "'Mr. Robot' has been the greatest experience with the greatest people, and I will be so sad when it's over," the Oscar-winning actor said at a Tribeca Film Festival panel discussion on Sunday. Sitting beside Malek at the event in New York were show creator Sam Esmail and co-stars Christian Slater and Carly Chaikin. "There's a lot of anxiety around what's going on in the world right now. I think Elliot tapped into that," Esmail said of the cybersecurity expert-turned-revolutionary that Malek plays. "The final season of 'Mr. Robot' is one very long Christmas special," he said. In an interview with Entertainment Tonight at the film festival, Malek said he thinks playing Eliot helped him land his Oscar-winning role in the Queen biopic, "Bohemian Rhapsody." "This seemed to propel me into a different space. I wouldn't have gotten the role of Freddie Mercury in Bohemian Rhapsody, if it wasn't for this show," Malek said. "American Idol" Season 8 runner-up Adam Lambert returned to the singing competition show Sunday night to mentor the Season 17 contenders as they took turns singing Queen's classic rock anthems. Lambert has been touring with the surviving members of Queen in recent years. Mercury died in 1991. He was 45. ABC will air a two-hour documentary Monday night, "The Show Must Go On: The Queen + Adam Lambert Story."