HAL KEEN MYSTERY STORIES

By HUGH LLOYD

Boys! Meet Hal Keen, that lanky, nonchalant, red-headed youth whose guiding star is the star that points to adventure, excitement and mystery. Follow him in his hunts for clues and criminals. There are plenty of thrills and shivers in these stories to keep you on your toes.

THE SMUGGLER’S SECRET

Hal Keen sets out to get to the bottom of a mystery that threatens the safety of a whole community.

THE MYSTERIOUS ARAB

Mystery, excitement, murder in a scientist’s camp in the jungles of Africa, where hate, revenge, and suspicion lead to tragedy.

THE HERMIT OF GORDON’S CREEK

The disappearance of two airmail pilots leads to a mystery that centers about an abandoned mine and a strange old man.

KIDNAPPED IN THE JUNGLE

A hint of buried treasure in the ruins of an old French mission leads Hal deep into the Central American jungle.

THE COPPERHEAD TRAIL MYSTERY

Baffling and blood-curdling events center about the ranch where Hal Keen and his friends had gone in search of gold.

THE LONESOME SWAMP MYSTERY

The lonely and mysterious swamp gave up its secret only after a series of terrifying events taxed Hal’s courage and ability.

THE CLUE AT SKELETON ROCKS

In this new thriller Hal Keen finds mystery and adventure in and about a lonely lighthouse on Skeleton Rocks, off the Maine coast.

THE DOOM OF STARK HOUSE

Mystery and terror in an old house in the wilderness above Quebec where Hal Keen is the guest of a strange family.

The AIR COMBAT STORIES for BOYS

By THOMSON BURTIS
Author of
The Rex Lee Stories

Zooming into the war scene comes this new hero of the air, Lieutenant Rudford Riley, who leads The Phantom Five, a group of airmen detailed for special duty in the Royal Flying Corps during the early days of the war when every take-off was an impudent challenge to death. The record of their mad exploits over the front makes breathless reading, and their adventures have the ring of truth in them for the author-flyer takes them from his own rich experience as a war-time aviator.

DAREDEVILS OF THE AIR

Recounts Lieutenant Riley’s adventures as leader of The Phantom Five against the enemy in the air.

FOUR ACES

As commanding officer of Special Flight A, Rud Riley and Jerry Lacey, the Manhattan Madman, are thrown into the thickest and hottest of the air fighting.

WING FOR WING

Continues the record of the daredevil young airman’s adventures as one of the leading aces in the war.

FLYING BLACK BIRDS

Stormy Lake leads a squadron of picked daredevils called the Black Birds against the famous German Red Devils led by Von Baer.

ADVENTURES in the UNKNOWN

By CARL H. CLAUDY

Weird! Mysterious! Incredible! Astounding!

Leap back a million years into the dark prehistoric ages. Speed through the dangers of outer space beyond the stratosphere at a thousand miles a minute. Meet the grotesque machine men of Mars. Break into the bounds of the Fourth Dimension. You will meet in these thrilling, fascinating stories many incredible beings and astounding sights that will stagger your imagination.

THE MYSTERY MEN OF MARS

Seventy million miles from home! Three men—a daring scientist and two adventurous boys—take off from the earth in a steel and aluminum sphere that sails through space at 20 miles a second. On the planet Mars they face destruction at the hands of beings who resemble mechanical bugs more than men!

A THOUSAND YEARS A MINUTE

In the world of a million years ago—whence they have been propelled by an old professor’s invention—Alan and Ted find themselves pitted against the dinosaurs, mammoths and savage ape men of a lost world.

THE LAND OF NO SHADOW

Through a violet coil frame in Professor Arronson’s laboratory Ted and Alan leap into the gray and terrifying land of the Fourth Dimension. There they are shadowed by the ghostly forms of menacing, bodiless shapes!