Jack Armstrong #3

Jack Armstrong and his friend Billy are captured by a mysterious pirate submarine operating off the southwest coast of Africa, where diamond-laden ships are being hijacked and destroyed. Forced to help the submarine’s captain, Ubél, install a long-range sonar system, Jack secretly uses a hidden radio to send a coded signal to Uncle Jim in Capetown, setting in motion a plan to expose the gang’s secret operation.

Doug and Max Bentley, brothers and stars of the Chicago Black Hawks, stand out as one of the most dominant hockey duos in league history, combining skill and synergy to lead the scoring charts and challenge even the best goalies. Their individual and shared achievements—record-breaking points, All-Star honors, and Max’s historic Hart Trophy win—highlight their impact on the sport during the 1940s.

Fifteen-year-old Richard Cunningham rushes to help a young boy who has stopped breathing, using his recently earned first-aid training to perform artificial respiration. As the child’s mother pleads for help and neighbors react in panic, Richard stays calm and acts quickly, applying life-saving techniques until the boy begins to breathe again. His quick thinking and training save the child’s life, earning him recognition as this month’s winner of the Jack Armstrong Adventure Magazine All-American Award.

In the case of the stolen diamond rings, a gun and bullet recovered from a gutter are sent to Vic Hardy’s crime lab for analysis. Using microscopic comparison, Hardy discovers the bullet matches the gun’s barrel markings, linking the weapon to a man named Jim Clark—whose connection to the crime deepens when the gun’s purchase record is traced.

Jack Armstrong ventures into the legendary Lost Valley of Ice with Billy, braving treacherous rapids and a dark, icy tunnel, while Betty and Uncle Jim fly above, only to crash into a hidden tropical valley. As Jack and Billy emerge into the valley’s mysterious heart, they discover a shocking secret behind the myths—only to be pursued by the very men who created the danger.

Billy takes on babysitting duty for Irma, a ten-month-old baby, while her parents go to a football rally. As he struggles to keep her entertained and calm, he accidentally wins a cash prize on a radio quiz show while holding the baby, leading to a surprising turn of events.