CSI: Crime Scene Investigation will not produce a full order of episodes for season 15.

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The long-running CBS drama will trim down their 22-episode schedule to 18, according to TV Line.

It appears the decision to truncate the season is one-part ratings and two-parts timing.

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CSI: Las Vegas is currently the only piece of the CSI franchise left standing, but that will change this spring as CBS roles out CSI: Cyber. Previewed during season 14 of the iconic procedural, Cyber is set to debut in its predecessor's timeslot, according to TV Line.

While the freshman series will have a guaranteed launching point at 10 p.m. ET on Sunday, this means that any extra Las Vegas episodes would have to move. Formerly on Wednesday nights, Las Vegas jumped to Sunday's in the absence of The Mentalist, which will return once more in early 2015. With such tight booking, it appears Las Vegas drew the short straw - a decision that may have been egged on by the series' falling ratings.

CSI enjoyed 9 to 10 million viewers during season 14 (down from season 13's 10 to 11 million), but those numbers fell into the 8 million range during this past month.

For now, viewers can catch CSI Sundays at 10 p.m. ET on CBS. Click the video below to see a review for the series' next episode, "Girls Gone Wilder."