Robin Williams was a comedian unlike no other, conquering the worlds of film, television and stand-up with an idiosyncratic sense of timing that helped him carve out a distinct presence as an entertainer. However, the actor also showcased versatility with critically-acclaimed roles in One Hour Photo and Gus Van Sant's Good Will Hunting, revealing that Williams was far from a one-trick-pony. 

Behind-the-scenes, Williams battled a crippling addiction to alcohol and some serious mental health issues, which eventually led him to commit suicide back in 2014. 

Robin Williams: Come Inside My Mind is a forthcoming documentary that will explore all aspect's of the late-comedian's life, including his crushing internal dilemmas. The film, which premiered at the Sundance Film Festival back in January, will feature rare, never-before-seen footage, alongside interviews with those who were close to him.

Steve Martin, a fellow comedian and close confidante, makes an appearance in the clip, revealing how Williams "was really comfortable onstage. Offstage, I just felt he was holding himself together."

Peep the emotional trailer below: