Limited series
Cosmic Boy was featured in a four-part limited series, cover dated December 1986 through March 1987. A tie-in to the Legends limited series, it was written by Paul Levitz, with art by Keith Giffen, Ernie Colón, and Bob Smith.
In the series, Cosmic Boy and Night Girl have traveled from the 30th century to enjoy a vacation in the 20th century. They find themselves threatened by many citizens and residents of the United States, who have been manipulated by Glorious Godfrey as part of Darkseid's scheme to discredit Earth's superhero community. Soon after arriving, Cosmic Boy encounters Superman, who does not recognize him despite Superboy being a member of the Legion for years. Cosmic Boy and Night Girl fear that something is terribly wrong with history. A space shuttle mission carrying a satellite crucial to Earth's future development of space travel goes awry, with the shuttle exploding. Cosmic Boy magnetically catches the payload and sends the debris harmlessly toward the ocean, but American soldiers assume that he is a foreign spy. They attack him, implementing Ronald Reagan's directive that outlaws all superhero activity.
Seeking to protect the satellite, Cosmic Boy and Night Girl travel to NASA facilities in Houston where they meet Jason, one of the astronauts who designed the shuttle. They help to quell a riot that breaks out when demonstrators break down the gates at NASA, and Cosmic Boy becomes convinced that some unseen enemy is deliberately trying to prevent the mission. As they depart, the couple notes that both of their families are from worlds settled during the Great Emigration from Earth. They are unaware that the last name of Jason — the astronaut they just met — is Krinnski, which implies that he may be a distant ancestor of Cosmic Boy.
Cosmic Boy and Night Girl return to the 30th century, where time travel experts Brainiac 5 and Circadia Senius may be able to determine the problem. Upon entering the timestream, their Time Bubble encounters a storm and shakes violently. They are forced to return to the 20th century. They turn to Jason Krinnski for assistance, who does his best to help them repair the Time Bubble. However, their second attempt to leave fails, as if there was a barrier blocking them. Realizing that they need a massive power source to propel the Bubble to the 30th century, Cosmic Boy harnesses energy from Earth's magnetic field. They breach the barrier, but are propelled to the end of time, where they confront the Time Trapper.
The Trapper toys with the couple, giving them an hour to return to the 30th century. They eventually make their way through the Trapper's Citadel to their Time Bubble, just as the last grains in the hourglass are about to fall. Cosmic Boy uses his power to warp the hourglass, closing it so that the last grain will never fall. Amused, the Trapper allows them to leave. He directs the Time Bubble to the 30th century, placing it right in front of Legion Headquarters. He warns the couple that this will be their final journey through time, and that "the next occasion when a Legionnaire dares break the time barrier will be the last". As the two of them race to warn the Legion about what has occurred, the Trapper realizes that the Legionnaires will be returning for him.
The events of this series are continued in the 1987 story arc "The Greatest Hero of Them All".
