William Mapother

Another Lost alum is making their way back to Hawaii!

William Mapother, who played one of the Others — the sinister Ethan Rom — has been tapped to guest-star on the upcoming season of Hawaii Five-0, according to Entertainment Weekly.

Exclusive: Hawaii Five-0 adds Crazy Ones alum Amanda Setton

Mapother, whose other TV credits include The Mentalist and Castle, will play Eric Porter, a wealthy business owner who gets pulled into a painful situation, but still offers to help the Five-0 team.

Mapother is far from the only Lost alum to appear alongside Hawaii Five-0 series regular and fellow former Lost star Daniel Dae Kim. Terry O'Quinn, Jorge Garcia, Henry Ian Cusick, Sam Anderson, Tania Raymonde and Francois Chau have all made it back to the island. (We have to go back, Kate!)

Hawaii Five-0 returns Friday, Sept. 26 at 9/8c on CBS.

(Full disclosure: TVGuide.com is owned by CBS.)

Watch This Tonight — See why Who Do You Think You Are? is today's editors' pick: