Watch ‘CSI: Crime Scene Investigation’ Finale Live Online: Streaming Video Of Sunday’s Two-Hour Movie

Fans can watch the CSI: Crime Scene Investigation finale live online and see just how the long-running series will come to an end after 15 seasons.

The two-hour movie finale will air Sunday, September 27, at 9 p.m. on CBS. Fans who aren’t able to make it to a television to watch the event will be in luck, with CBS offering the movie available for online streaming.

Those who tune in will get to see a few familiar faces returning. William Peterson will return as character Gil Grissom, and Marg Helgenberger will also be back to play Catherine Willows.

In an interview with The Hollywood Reporter, Helgenberger said fans will have some other surprises in the CSI finale.

“There’s a big fan favorite that’s returning — Melinda Clarke, who played a character that appeared several times on the show by the name of Lady Heather. She sort of becomes a suspect. Then, there’s homages throughout the whole episode — lines that were memorable [earlier in the series], somebody repeats that line [in the finale], [but] not necessarily the same character. (Laughs.) My daughter returns, who’s now grown. I think the fans are just going to appreciate seeing everyone together again and solving a crime as a unit.”

Helgenberger added that fans of the show will have plenty of closure by the time the two-hour movie comes to an end.

“I think the fans would have been disappointed and upset if it just ended without any finality,” Helgenberger said.

It once seemed as if fans may not get much finality with the show coming to an end last year, but CBS opted for a one-time event to bring the popular series to a conclusion.

Those who watch the CSI finale live online will see an exciting cap to the show’s long run, Helgenberger noted. She said the two-hour finale has a “real energy” and refers to the episode as a “ticking clock.” Without going into many details, she said the crew will be trying to stop a criminal who has attacked in Las Vegas and could be planning to strike again.

That criminal could be connected to Gil Grissom’s friend, the dominatrix Lady Heather.

“It takes many twists and turns, but you’ll see a lot of old-school CSI in the storytelling, getting back to basic forensics,” series creator Anthony Zuiker told CBS News.

Those who want to watch the CSI finale live online can click here to get streaming video through CBS on Demand.

[Image via CBS Promo/TV Guide]