Death on the bridge

Three months ago, Cambri Nguyen drove to a remote bridge in the state of Montana and jumped from a height of two hundred feet, dying on impact. At least, that's the official version of the police. But her twin sister Lena doesn't believe it. She drove to the same bridge in her deceased twin's car, armed with a cassette recorder, to find out what really happened by questioning the highway patrol officer who discovered her sister's body. Corporal Raymond Ricevik agreed to meet Lena at the scene, but his story doesn't add up. Why did Cambri make sixteen attempts to call 911 shortly before her death? Why did she send a mysterious message to her sister? Lena is willing to do whatever it takes to uncover the truth.