Dominic Monaghan has signed on as narrator for the anthology series "The Unknown" for Crackle, the online video network said.

The series will consist of six half-hour standalone episodes, which fuse "drama, psychological thrills, suspense and horror while examining mysterious phenomena," the network said in a news release Monday.

Monaghan is best known for his work in the "Lord of the Rings" films and the TV series "Lost." In "The Unknown," he will play Mark Nickel, a blogger who chronicles the unexplained phenomenon that occurs in each individual episode, bringing the characters' stories to life. Mark will be the only character who appears in all of the episodes.

Also to appear on the show are Frances Fisher, William Atherton, Taryn Manning, Jay R. Ferguson and Christina Pickles.

Directors of individual episodes include actor-director Kevin Connolly, visual-effects specialist Sam Nicholson and director Martha Coolidge.

"The Unknown" is to debut this year on