Someone will die on the second episode of Hawaii Five-0 Season 3. The official CBS description for that October 1 installment has already given as much away.

But how will Steve McGarrett react to the return of his mother? How will Christine Lahti's character find herself in crossfire on the September 24 premiere? Those are two of the question teased in the first trailer for upcoming episodes.

Click Play now to watch new footage from the season ahead and let the countdown begin. We return to the action-packed island life in under a month...

Matt Richenthal is the Editor in Chief of TV Fanatic. Follow him on Twitter and on Google+.