Comic Title: Green Lantern #21
Publisher: DC (National Periodical Publications, Inc.)
Address: 575 Lexington Avenue, New York, NY
Cover Date: June 1963
On Sale Date: April 4, 1963 Copyright Date April 4, 1963
Source: Library of Congress, Periodicals 1963

Frequency: Monthly, with the exception of Feb., May, Aug. and Nov.
Cover Price: $0.12
Page Count: 32
Editor: Julius Schwartz

Title: "The Man Who Mastered Magnetism"
Pages: 15

Feature(s):
Green Lantern (Hal Jordan of Earth-1)

Writer: John Broome
Penciller: Gil Kane
Inker: Joe Giella

Reprinted In:
Green Lantern Archives Vol. 3 HC (2001)
Showcase Presents Green Lantern Vol. 2 TPB (2007)
Green Lantern Omnibus Vol. 1 HC (2011)
Green Lantern:The Silver Age Omnibus Vol. 1 HC (2017)
Green Lantern:The Silver Age Vol. 2 TPB (2018)

Feature Character(s)

• Green Lantern (last appearance in Justice League of America #19; next appearance in Green Lantern #21)

Supporting Character(s)

• Tom Kalmaku (last appearance in Green Lantern #19; next appearance in Green Lantern #21)

Villain(s)

• Doctor Polaris (next appearance in Justice League of America #35)

Other Character(s)

• Various citizens of Coast City (no further appearances)

Synopsis:
In a hospital room, Green Lantern uses his power ring to learn the story behind the unconscious man lying in the bed. His name is Dr. Polaris, and he gave lectures about the benefit of magnetism on human health. Some were skeptical about his ideas, but others embraced his ideas wholeheartedly. During his lectures, he would demonstrate magnetic tricks to amuse his audience, but primarily he was delivering his message that magnetism is benefical to a person’s health.

Polaris gained much popularity and was asked to speak at many functions. At one such function, a man in a costume robbed the box office using magnetic devices. Green Lantern was called in to investigate. He visits the home of Dr. Polaris and finds the masked thief out front. He apprehends the man and discovers it is Dr. Polaris himself.

In the hospital Green Lantern learns more about Dr. Polaris. In medical school he had a fanatical interest in magnets. He began subjecting himself to powerful electro-magnets which strengthened his body. He also made many magnetic discoveries. However too much magnetic energy had another effect on him. He developed a split personality. The new personality was evil and wore the costume.

Polaris manages to escape from the hospital, so Green Lantern pursues him. Polaris uses a magnetic weapon against GL which causes steel girders to be attracted to him. The power ring reverses the effect, and Green Lantern overcomes his opponent. Polaris is turned over to the authorities, and his good side is once again in control.