Jacob, his nemesis returning to 'Lost'

Titus Welliver, Mark Pellegrino to appear in final season

With "Lost" fans eager for answers in the final season of the ABC drama, at least one of the show's mysteries may get resolved: Who is Jacob's nemesis?

Titus Welliver, who played a mysterious character in Season 5, is set to reprise his role in the second part of "Lost's" sixth season, which premieres Feb. 2.

To make things even more suspenseful, also returning for the final season is Mark Pellegrino, who played Jacob. He will appear in at least six episodes of "Lost's" final, 18-episode season.

It's a safe bet the the two will probably meet again.

Jacob's nemesis (aka Man in Black), who last appeared in Season 5's finale, is an inhabitant of the island who had spent a century looking for ways to kill Jacob, the mysterious leader of the Others, until finally succeeding in 2007 by assuming the appearance of the dead John Locke (Terry O'Quinn) and persuading Benjamin Linus (Michael Emerson) to stab Jacob.

The Man in Black's name, identity, motives, backstory and bone of contention with Jacob were never revealed, leading to a flurry of speculation among "Lost" fans about who he really is.

Similarly, there is an ongoing discussion about the origin of Jacob, who has been a significant presence on "Lost" since Season 2 until finally revealed onscreen at the end of Season 5.

Paradigm-repped Welliver recurs on CBS' freshman drama "The Good Wife" as scheming district attorney Glenn Childs and also recently did an arc on the FX drama "Sons of Anarchy."

Pellegrino, who recurs on the CW's "Supernatural," is repped by Domain and Framework.

A number of castaways will be returning to the island for "Lost's" final season.

The show's showrunners Damon Lindelof and Carlton Cuse recently said Harold Perrineau and Cynthia Watros are coming back to reprise their roles.