Gil Grissom's back! The first teaser for CSI's two-hour finale has arrived with our first glimpse of William Petersen and Marg Helgenberger joining Ted Danson and other CSI alums for one last hurrah.

We also catch just a hint of Grissom and Sara Sidle's (Jorja Fox) relationship status, as guest star Melinda Clarke asks Sidle, "Do you love him?"

Take a look at the promo below to see what she said, and let us know how you think the special event will tie up 15 seasons of stories.

CSI's finale event airs Sunday, Sept. 27 on CBS.

(Full disclosure: is owned by CBS)