Comic Title: Superboy #158
Publisher: DC (National Periodical Publications, Inc.)
Address: 909 Third Avenue, New York, NY
Cover Date: July 1969
On Sale Date: May 20, 1969 Newsstand Date May 20, 1969
Source: House Ad, Action Comics #378, Page 31

Newsstand Date May 20, 1969
Source: Comic Reader, #73

Copyright Date May 20, 1969
Source: Library of Congress, Periodicals 1969

Frequency: Monthly, with the exception of February, August and November
Cover Price: $0.15
Page Count: 32
Editor: Murray Boltinoff

Title: "Superboy's Darkest Secret"
Pages: 24

Feature(s):
Superboy (of Earth-1)

Writer: Frank Robbins
Penciller: Bob Brown
Inker: Wallace Wood

Feature Character(s)

• Superboy (last appearance in Superboy #157; next appearance in Superboy #159)

Supporting Character(s)

• Jonathan Kent (last appearance in Superboy #157; next appearance in Superboy #159)
• Martha Kent (last appearance in Superboy #157; next appearance in Superboy #159)
• Jor-El (last appearance in Action Comics #223; no further appearances)
• Lara (last appearance in Action Comics #223; no further appearances)

Villain(s)

• Val Arn and Khai Zor (Var Arn dies in flashback; Khai Zor now called Xonar; last appearance in Action Comics #223; no further appearances)

Other Character(s)

• Dr. Krylo (dies in this story; no further appearances)

Comments:
This story expands the story of Krypton's destruction. The bodies of Jor-El and Lara are placed in a rocket and survive the explosion of the planet. They could potentially be revived, but Superboy learns that his parents were already dying from K-radiation exposure. If they were revived, they would suffer a second agonizing death.

Synopsis:
Superboy received a message from deep space from his Kryptonian father Jor-El. Investigating, he discovers the bodies of Jor-El and Lara in a space capsule surrounded by Kryptonite radiation. He is then pushed close to the capsule by Xonar, an old foe of his father. Superboy is rescued by Dr. Krylo, another Kryptonian and is taken to safety.

Krylo explains that he was able to cryogenically preserve himself and Superboy's parents even though Jor-El did not want to be preserved. Superboy and Krylo then enlist the aid of Jonathan Kent to retrieve the capsule. Xonar strikes again to stop them, but Superboy fights him off. The villain then crashes into a space mine and is killed.

Krylo exposes himself to the Kryptonite to save Jonathan. Superboy then takes the bodies of his parents back to Earth hoping to revive them. However, a recording inside the rocket explains that both Jor-El and Lara were dying of radiation poisoning before they were placed into the rocket by Krylo. Reviving them would only lead to another painful death, so Superboy leaves their bodies in the rocket and returns it to deep space.