Diana Duve was 26 when she vanished one night in 2014 in Vero Beach, Fla. She was last seen alive leaving a bar with her on-again, off-again boyfriend, Michael Jones. To witnesses, the couple seemed to be having a good time, though they told police that at one point it looked like Duve was upset. She never returned home. Her mother knew something was wrong when her daughter didn't call her, something she did every day. Contributor Michelle Miller and 48 HOURS report on what happened that night.