Oksana Grigorieva will appear tonight on Larry King Live, and when she does, she will reveal for the first time why that she taped conversations with Mel Gibson.

His legal team says, or at least strongly insinuates, that it was all done as of a plot to extort him for money. They cite her emails as proof of sinister intentions.

Her explanation? She thought she was going to die.

HE SAID, SHE SAID: Or more like he screamed, she recorded.

"I started taping it around 11 o'clock because I thought, 'I'm actually not going to live through the night. I'm not going to live through the night," she said.

Grigorieva said she hoped her mom would share the tapes with the police. "I wanted my mother to be able to prove that if I'm dead that this is who did it."

Anyone buy that? While the Mel Gibson rants were terrifying and the actor has rage issues beyond belief, she sounded awfully calm on the recordings.

As for why she stayed with Mel despite his behavior - he admits slapping Oksana but says it was to protect Lucia - Grigorieva admits it was a mistake.

"I stayed too long," she said. "I gave him the last chance. He asked for the last chance. He begged. He cried on his knees. What am I supposed to do?"