The "CSI" team has one last case to solve together, but the bigger mystery looming in the series finale is the relationship status between exes Gil Grissom and Sara Sidle.
Their romance takes center stage in the first promo for the original "CSI," which will end its 15-season run with a two-hour series finale on Sunday, Sept. 27. Grissom (William Petersen) and Sara (Jorja Fox) both express an interest in rekindling their love after their divorce two years ago.
"I miss working side by side with you," Grissom tells his ex.
The promo also features Grissom's other love interest over the years, Lady Heather (Melinda Clarke) and her possible involvement in the CSI's latest case. Sara even admits to her that she's still in love Grissom despite their rocky past.
The new and old CSI teams will unite to investigate an explosive attack on the Eclipse casino, co-owned former CSI Catherine Willows (Marg Helgenberger) who now works for the FBI.
Petersen returns to the show for the first time in six years. The show continued his storyline with Fox despite his absence (and hers for a season) until it ultimately split the couple in season 13.
Catch the "CSI" two-hour series finale on Sunday, Sept. 27 at 9 p.m. on CBS.
