Not content with playing the man (well, potential man) behind the curtain on ABC's island drama, Pellegrino will also be appearing in the CW's slacker Buffy bros series as Lucifer himself when the show returns this fall. Fans of the series already know that Mr. Morningstar was released in the season finale of the show's fourth season, but the September 10th season premiere will be our first chance to see the devil himself in action.

Pellegrino is joining the series as a recurring guest-star, meaning that this new role is likely to allow him all the Lost time he needs to wrap that story up in its final season, to launch next year.

'Lost' star finds hellish 'Supernatural' gig [Entertainment Weekly]

According to EW, Pellegrino will turn up in the season finale, playing the mysterious Jacob. And Pellegrino is going to be turning up all over the place.

Rumor has it that Jacob meets Young Sawyer at Sawyer's mother's funeral, in a flashback.

Not only that, but fans spotted Pellegrino filming a scene where Jacob is sitting on a bench outside a building, reading a book. And then Locke falls eight storeys out a window, and lands behind him. People yell for help and call 911. Jacob calmly puts a bookmark in his book, and then walks slowly over to Locke's bloody, battered body and kneels next to him in the grass.

Another eagle-eyed fan also spotted someone who looked like Pellegrino on the scene during a new batch of filming of what appeared to be the death of Sayid's beloved Nadia. (More pics at the link.)

So rumor has it that Jacob is visiting our heroes at crucial points in their history. He's showing up at Sun and Jin's wedding, Sawyer's mom's funeral, Nadia's death and Locke's fall. What could it all mean?