It's always a safe bet when Groucho Marx is on hand, especially when he's hosting the madcap game show You Bet Your Life. The legendary comedian and rapid-fire ad libber keeps things moving (and audiences laughing) as pairs of contestants wager their way through trivia questions to a grand prize. And there may be a secret word dropped along the way. We'll hear a pair of episodes originally aired on NBC on March 10, 1948 and April 14, 1948.

To celebrate Arthur Conan Doyle's birthday, we'll hear radio adaptations of four Sherlock Holmes short stories, each featuring a different actor as the great detective. First, Basil Rathbone stars in "The Speckled Band" (originally aired on Mutual on November 12, 1945). Next, we'll hear Tom Conway in "The Adventure of the Dying Detective" (originally aired on ABC on February 3, 1947). Then, it's "The Adventure of the Empty House" (originally aired on Mutual on April 11, 1948). Finally, John Gielgud plays Holmes in "The Bruce-Partington Plans."

In this week's bonus comedy episode, Jack Benny, Mary Livingstone, and Cecil B. DeMille star as themselves in a delightful comedy mystery from The Lux Radio Theatre. The trio headlines "Seven Keys to Baldpate," the mystery novel turned smash comedy play that was brought to the silver screen several times. This production originally aired on CBS on September 26, 1938.

Sam Spade made a dynamic debut in Dashiell Hammett's The Maltese Falcon before lighting up the big screen in John Huston's classic noir drama. In 1946, Spade came to radio in a weekly series of adventures that became a critical and listener favorite. We'll hear Howard Duff in "The Bail Bond Caper" (originally aired on CBS on June 27, 1948) and "The S.Q.P. Caper" (AFRS rebroadcast, originally aired on CBS on November, 1948). Then, Steve Dunne is Spade in "The Sure Thing Caper" (originally aired on NBC on February 9, 1951).

It's a double feature of classic comedy films recreated for radio in this week's bonus episode. Bob Hope reprises his screen roles in two productions from the Screen Directors' Playhouse: "The Ghost Breakers" (originally aired on NBC on April 3, 1949) and "The Paleface" (originally aired on NBC on March 3, 1950).

Jeff Regan wasn't a lone wolf operator like other radio gumshoes; he reported to Anthony J. Lyon, head of the International Detective Bureau. Known throughout the city as "the Lyon's Eye," Regan worked cases sometimes in spite of the penny-pinching interference of his boss. We'll hear Jack Webb as Regan in "The Diamond Quartet" (originally aired on CBS on August 14, 1948) and "The Man Who Came Back" (originally aired on CBS on August 21, 1948). Then Frank Graham stars in "No Sad Clowns for Me" (originally aired on CBS on June 25, 1950).

Spring is in the air on this week's bonus comedy quarantine show. We'll hear an unseasonable prediction of snow on Fibber McGee and Molly (originally aired on NBC on May 11, 1943). Then, Uncle Miltie and his gang present their salute to the season in The Milton Berle Show (originally aired on March 23, 1948).

Thrill to the exploits of America's newspaper reporters in The Big Story with dramas of the hard work of the men and women of the press. The true tales ripped from the pages of America's papers made for compelling - and popular - radio. We'll hear two stories of reporters who double as detectives to get to the bottom of murder cases and - in one instance - clear a wrongfully convicted man. We'll hear "The Deadline Murder" (originally aired on NBC on May 19, 1948) and "The Bitterest Man on the Earth" (originally aired on NBC on June 8, 1949).

With Mother's Day right around the corner, our midweek bonus comedy show features visits from a pair of mothers-in-law much to the chagrin of George Burns and Lucille Ball. First, Gracie's mom comes to town in The Burns and Allen Show (AFRS rebroadcast from May 20, 1948). Then on My Favorite Husband, George's mother's visit stretches on and on...and on (AFRS rebroadcast from March 4, 1949).

Even though he could leap tall buildings in a single bound and bend steel in his bare hands, most of Superman's radio adventures were down to earth. In many shows, the Man of Steel (and his alter ego Clark Kent) battled gangsters and swindlers rather than mad scientists and monsters. We'll hear Clayton "Bud" Collyer as Superman with Joan Alexander as Lois Lane in two thirty-minute mysteries: "One Minute to Death" (originally aired on ABC on November 19, 1949) and "The Diamond of Death" (originally aired on ABC on December 17, 1949).