Gil Grissom, Catherine Willows return for 2-hour CSI series finale

In 2000, CSI: Crime Scene Investigation was a last-minute pickup by CBS, a quirky little drama dwelling on hair fibres and blood spatter that was plugged into a Friday lineup. It was an out-of-nowhere smash that spawned two long-running spin-offs and recently gave birth to a third, CSI: Cyber, which now will survive it as the original comes to an end.