More DOAs and OCDs this season

After Dan Hedaya's memorable appearance as Monk's dad on the recent holiday episode, the award-winning series will return with even more guest stars for its fifth season, which kicks off in January.

Among the illustrious actors joining Tony Shalhoub is "Lord of the Rings" hobbit Sean Astin. On the show, Astin will play the son of a wealthy couple (Holland Taylor, Michael Cavanaugh), neighbors of Natalie's parents. When the couple mysteriously dies, Monk questions the son while investigating the possiblity of foul play.

Astin, best known as the loyal hobbit Sam from the LOTR films, also guest starred on "24," and provided the narration for Animal Planet's popular "Meerkat Manor."

"Monk's" new season also boasts other guest stars, including: "Studio 60" actor Steven Weber, Ricardo Chavira ("Desperate Housewives"), Charles Durning, "Frazier's" Dan Butler, David Eigenberg, funnyman Andy Richter, Heather Tom, James Gammon, Chris Williams and Brooke Adams.

Fans of the show can look forward to more mysterious mayhem this season, including:

Monk investigates a radio shock jock (Weber) as a suspect in his wife's murder, but the DJ was on the air at the time of the killing.

Monk makes a new friend, the laid-back guy Hal (Richter), but Hal may have an ulterior motive.

The detective competes against a federal agent (Williams) and his flashy forensic technology in the pursuit of San Francisco's "Six Way Killer."

When Monk gets a bloody nose, he goes to the emergency room, but gets pulled into a life-threatening muder investigation when a doctor turns up dead.

Monk helps Lt. Disher investigate the alleged suicide of an uncle who left the cop a farm.

"Monk" is one of the highest-rated original scripted series in basic cable history and has earned Shalhoub three Emmys for portraying the brilliant detective who suffers from obsessive-compulsive disorder, a problem that he must circumvent in his daily life and to solve crimes. Howard, Ted Levine and Jason Gray-Stanford also star.

The new season begins on Friday, Jan. 19.