Issue 1
Challengers of the Unknown (1958-) #1
"The Man Who Tampered with Infinity." A mad scientist uses an "infinity machine" to teleport monsters from other dimensions. "The Human Pets." An alien boy collects "animals."
Issue 2
Challengers of the Unknown (1958-) #2
"The Monster Maker." Ace fights a criminal who uses a mind-over-matter machine. "The Traitorous Challenger." June Robbins sees a computer that predicts that the Challengers will die if they battle an atomic creature.
Issue 3
Challengers of the Unknown (1958-) #3
"The Secret of the Sorcerer's Mirror." The Challengers face a villain who intends to use a sorcerer's tool that will give him magical powers. Plus, "The Menace of the Invincible Challenger." An alien chemical gives Rocky superpowers, but also drives him mad.
Issue 4
Challengers of the Unknown (1958-) #4
The Challengers of the Unknown are called in to investigate an apparent Greek soldier who has appeared in modern times and stolen a plane and other artifacts. They learn that he was summoned by the "wizard of time," a scientist named Darius Tiko who intends to use a time cube to travel to the future and bring back powerful weapons to the present!
Issue 5
Challengers of the Unknown (1958-) #5
After receiving reports of a super-powered criminal who has gained mystical flame powers, the Challengers are called by June Robbins to an archaeological expedition. She and Professor Brandon are seeking the mysterious Star-Stone, a powerful stone that would grant temporary powers. When it becomes known that someone is finding each of the four stones, and using them for ill-gotten gain, the Challengers undertake to bring this person to justice.
Issue 6
Challengers of the Unknown (1958-) #6
After receiving reports of a super-powered criminal who has gained mystical flame powers, the Challengers are called by June Robbins to an archaeological expedition. She and Professor Brandon are seeking the mysterious Star-Stone, a powerful stone that would grant temporary powers. When it becomes known that someone is finding each of the four stones, and using them for ill-gotten gain, the Challengers undertake to bring this person to justice.
Issue 7
Challengers of the Unknown (1958-) #7
An explorer calls on the Challengers to help him subdue three alien creatures: a giant armadillo-like creature, a giant jelly-fish, and a giant fire-breathing bird. Can the Challengers help catch these creatures or will it be their doom?
Issue 8
Challengers of the Unknown (1958-) #8
The Challengers are visited one day by their honorary member June and her friend Mary, who have brought them a scroll which she found in a castle she had inherited in the land of Mordania. Showing the Challengers tThe scroll intrigues the group enough to check the castle out, but what they find is not what they were expecting!
Issue 9
Challengers of the Unknown (1958-) #82
"THE LURKER BELOW." Prof is dying of an all-consuming fungus infection. Rocky, June, Ace and Red rush him to their jet. Gaylord Clayburne, playboy/Challenger wannabe, learns Prof is sick and finds a specialist to heal him. Ignoring Clayburne, the Challengers zoom off to Perdition, Pennsylvania, a farm town, but as soon as they land, the Challengers are mobbed by farmers with pitchforks. Dr. Monroe calls off the farmers and relates the town's history to the Challengers. Seventy years ago, a man summoned a demon to the town. Enthralled, the locals sacrificed strangers to the "god" until Swamp Thing came to town and collapsed its cave, burying the monster "forever." Behind the scenes, we see the fungus lived on and still infects many locals.
Issue 10
Challengers of the Unknown (1958-) #83
"SEVEN DOORWAYS TO DESTINY!" The cultists have June as a hostage. The Challengers get beaten down by cultists, some half-monster. Monroe explains how M'Nagala came from the stars, as recounted in SWAMP THING #8. He demands Rocky and Ace fly to England and perform an incantation from a mystical book and bring M'Nagala's "family" to Earth. They go, reluctantly. At Challengers Mountain, Clayburne (the wannabe Challenger) uses the computer to analyze Prof's infection. It recommends Dr. Alec Holland as an expert in "biochemical abnormalities." Clayburne flies to Oregon, where Holland teaches, and he agrees to help. Outside London, Rocky chants at midnight in a pentacle, while Ace fetches a pack of jet fuel. M'Nagala-kin try to burst through a portal, all icky tentacles and squishy guts, but Ace chucks the fuel pod "just like Jaws" and shoots, destroying the monster and shutting the portal. Clayburne and Holland land in Perdition, but in the dark, Holland starts to revert to Swamp Thing as his bio-restorative formula wears off. They find Prof half-consumed by icky polyps.
Issue 11
Challengers of the Unknown (1958-) #84
"TO SAVE A MONSTER/WHEN DEADMEN WALK." Prof is infected with an alien fungus. Swamp Thing watches from cover and is attacked by a wolf, but brushes it off. The wolf is possessed by Deadman, who asks Rama Kushna why he's there. Back at Challengers Mountain, the heroes can't cure Prof's disease. Angry, Ace orders Gaylord to take a walk, which he does. Deadman tries a cure, diving in to possess Prof and fighting from within. Prof sloughs off the fungus and Deadman passes out. Prof wakes, healthy, and announces that Swamp Thing is Dr. Alec Holland, who's wandered off and needs help. The Challengers search, but Swamp Thing has hopped a freight for Philadelphia. Deadman tries to possess Swamp Thing and bounces—he's already possessed! Deadman possesses Ace and announces that Swamp Thing is in Philly, where Swamp Thing rages to the state asylum and the cell of Duncan Pramble, the former Multi-Man.
Issue 12
Challengers of the Unknown (1958-) #85
"THE CREATURE FROM THE END OF TIME!" A giant box appears in Toronto, and the Challengers, accompanied by Swamp Thing and Deadman, investigate. When Deadman tries to enter the box, it opens and releases a monster. After they kill the monster, the Challengers haul the box and carcass to Challengers Mountain, where tests indicate the box is from the future. The heroes fly to Rip Hunter's desert lab, which appears abandoned. Swamp Thing pushes a button and Rip's Time Sphere appears with a skeleton inside. They use the time sphere to travel to 12,000,000 AD. Amidst crumbling ruins, they are surrounded by future-men and Rip Hunter in rags and a crown.
Issue 13
Challengers of the Unknown (1958-) #86
"THE WAR AT TIME'S END." In the present, Prof is wheelchair-bound in Challengers Mountain, where he is attacked by a mutant lizard from the future. Future-boxes keep releasing monsters around the world, and Red (who quit) battles some in the streets. In the future, Rocky, Ace, June, Swamp Thing and Deadman find Rip Hunter (and his crew) are brainwashed pawns of the despotic Sunset Lords. After a fight, they're overwhelmed and captured, but Deadman, sneaking around in a borrowed body, meets Lucas Lawspeaker and his rebels.
Issue 14
Challengers of the Unknown (1958-) #87
"TWELVE MILLION YEARS TO TWILIGHT." In 12,000,000 AD, Ace, Rocky and June make a prison break, while Swamp Thing holds back mutants. Back in 1978 Prof is saved from a monster when Red returns, cranks up the lab temperature and cooks the creature, as the Justice League routs the remaining monsters. In the future, the Challs reach the breeder labs and blow them up as Swamp Thing battles the giant Persuader. Lawspeaker—the leader of the rebellion—arrives with the cavalry, his rebel Sky Riders. The Sunset Lords try to destroy the city, but Deadman possesses Rip Hunter to destroy their weapon, and the heroes head home.