Lisa Marie Presley's raw memoir "From Here to the Great Unknown" is out now. Ahead of Oprah's Riley Keough interview, these are the biggest reveals.

In the memoir, Lisa Marie Presley details the toll that her legendary dad's death - when she was just nine - took on her. For the first time, she describes waking up on the afternoon that he died in August 1977 and sensing something was wrong, before running into her father's room across the hallway and seeing him facedown on the bathroom floor.

Riley Keough has unveiled a heartbreaking letter written by her late mother, Lisa Marie Presley, in which she begged her father Elvis not to die. Elvis Presley, who died in 1977 aged just 42, suffered with health problems in his later life – his daughter Lisa Marie was only nine years old at the time of his death.