Ante up for three radio mysteries involving gamblers and the sometimes deadly bets they make. First, a pet shop owner is killed when he refuses to offer his store as a front for a gambling ring in Boston Blackie. Then, a real-life Chicago reporter cracks the case of a poker game that ends in murder on The Big Story (originally aired on NBC on April 4, 1951). And finally, Sgt. Joe Friday hunts for floating games in the City of Angels in "The Big Gamble" from Dragnet (originally aired on NBC on May 8, 1952).

It's a concert of crime in this week's episode, as two radio detectives tackle cases in the music world. First, Simon Templar investigates when a pianist is shot and killed at the keys. Vincent Price stars in "A Sonata for Slayers" from The Saint (originally aired on NBC on June 18, 1950). Then, Bob Bailey stars as Johnny Dollar in "The Ricardo Amerigo Matter," where "America's fabulous freelance insurance investigator" hunts for a missing violinist and his violin (originally aired on CBS between January 16 and January 20, 1956).

Hercule Poirot - Agatha Christie's brilliant Belgian sleuth - is back on the big screen in A Haunting in Venice. To celebrate his return, we'll hear three old time radio adventures of Poirot starring Harold Huber as the detective. We'll hear "Death in the Golden Gate" (originally aired on Mutual on May 17, 1945), "The Adventure of the Money Mad Ghoul" (originally aired on Mutual on September 13, 1945) and the series' audition episode "The Case of the Roving Corpse."

Actor Alan Ladd was born 110 years ago this month, and we're celebrating his life and career with four of his old time radio appearances. He plays mystery writer and amateur gumshoe Dan Holiday in "Diamond in the Sky" and "The Professor and the Puzzle," a pair of syndicated adventures from Box 13. Plus, he recreates his big screen role (and reunites with Veronica Lake) in The Blue Dahlia from The Screen Guild Theatre (originally aired on NBC on April 21, 1949) and he steps into the shoes of Walter Neff in Double Indemnity from Hollywood Star Time (originally aired on CBS on June 22, 1946).

It's time to sharpen those pencils and hit the books with four radio mysteries set in and around the classroom. First, a chemistry professor tries a blackmail experiment in "Hasty Conclusion" from The Whistler (originally aired on CBS on May 19, 1947) and Philip Marlowe's latest client is a Nebraska schoolteacher caught up in mystery and murder in "The Rustin Hickory" (originally aired on CBS on September 10, 1949). Then, Dana Andrews tries to thwart a Commie plot to infiltrate a college campus in "Little Red Schoolhouse" from I Was a Communist for the FBI and Joe Friday goes back to school to find an assailant targeting students in "The Big Knife" from Dragnet (originally aired on NBC on May 11, 1950).

In this bonus show, I'm opening the mail and picking out my five favorite episodes of Box 13. Alan Ladd stars as mystery writer and amateur detective Dan Holiday who finds his clients - and his story ideas - through a clever classified ad offering his services as an adventurer for hire. First, Holiday is hired to pose as a fiance in "Look Pleasant, Please" and he's pressed into a citywide scavenger hunt alongside a killer in "The Better Man." He works to save an innocent man from execution in "Hunt and Peck" and expose a cadre of crooked gamblers in "Much Too Lucky." Finally, a weekend getaway lands Holiday in the middle of a bitter family reunion and a series of dangerous practical jokes in "Death is No Joke."

Crime takes a dive in this week's episode of old time radio mysteries involving submarines, salvage divers, and the mysterious ocean floor. First, a love triangle leads to death at sea in "Dark Voyage" from The Whistler (originally aired on CBS on April 9, 1950). Then, Herbert Marshall hunts for a submarine targeting ships off India as The Man Called X (originally aired on NBC on February 3, 1951). And finally, G-men are on the job when a Nazi submarine drops off enemy agents in "The Saboteurs" (originally aired on ABC on March 30, 1951).

Danger flies high today with three old time radio mysteres involving airplanes. First, Frank Race is hired to deliver the plans for a million-dollar aircraft in the syndicated story "The Airborne Adventure." Next, Philip Marlowe's latest case leads to a team of daredevil skydivers and a deadly accident in "The Birds on the Wing" (originally aired on CBS on November 26, 1949). And finally, Douglas Fairbanks, Jr. stars as a government agent hunting for the person who stowed a time bomb aboard a plane in "The Big Kill" from The Silent Men (originally aired on NBC on February 3, 1952).

The world of art and artists provides the backdrop for our four old time radio mysteries. First, Basil Rathbone and Nigel Bruce are Sherlock Holmes and Dr. Watson hunt for a stolen painting in "The Girl with the Gazelle" from The New Adventures of Sherlock Holmes (originally aired on Mutual on March 25, 1946). Next, an artist's sketch leads to a new adventure for Rocky Jordan in "Portrait of Rocky" (originally aired on CBS on April 3, 1949). Edmond O'Brien is on the case of a $250,000 art gallery heist in "The Missing Masterpiece" from Yours Truly, Johnny Dollar (originally aired on CBS on March 28, 1950). And finally, a forged painting leads to a new case for Mr. and Mrs. North in "Collector's Item" (AFRS rebroadcast from February 9, 1954).

It's an explosive adventure for the Man of Steel as he tries to thwart a plot by foreign spies. This adventure originally aired between April 21 and May 9, 1941.