Comic Title: Adventure Comics #400
Publisher: DC (National Periodical Publications, Inc.)
Address: 909 Third Avenue, New York, NY
Cover Date: December 1970
On Sale Date: October 29, 1970 Newsstand Date October 29, 1970
Source: Direct Currents, Action Comics #395, Page 19

Copyright Date October 29, 1970
Source: Library of Congress, Periodicals 1970

Frequency: Monthly (semi-monthly, March)
Cover Price: $0.15
Page Count: 32
Editor: Mike Sekowsky

Title: "Return of the Black Flame"
Pages: 22

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

Writer/Penciller: Mike Sekowsky
Inker: Jack Abel
Letterer: John Costanza

Feature Character(s)

• Supergirl (last appearance in Action Comics #395; next appearance in Adventure Comics #401)

Villain(s)

• Black Flame (last appearance in Action Comics #304; next appearance in Krypton Chronicles #1)
• Inventor, L. Finn, and the Toymaster (Phantom Zone prisoners; no further appearances)

Other Character(s)

• A television announcer (no further appearances)

Comments:
Supergirl is exposed to Gold Kryptonite in this story, but somehow instead of immediately robbing her of her powers permanently she retains them claiming that prolonged exposure is needed. This contradicts every other story featuring Gold Kryptonite.

Additionally, Black Flame recruits three inhabitants from the Phantom Zone to assist her. None appear to affected by either Green or Gold Kryptonite. It should therefore be assumed that not all Phantom Zone inhabitants are Kryptonian. Additionally, Supergirl sends the villains into space at the conclusion of the story. The caption indicates that this is toward the Phantom Zone. No mention of the Phantom Zone projector is made during their release or return which casts more doubt on whether they are really from the Phantom Zone.

Synopsis:
The Black Flame escapes her imprisonment in the bottle city of Kandor. She then recruits the Inventor, L. Finn, and Toymaster from the Phantom Zone. This foursome then lures Supergirl into a trap. After weakening the Girl of Steel with Kryptonite, the villains tie her to giant bowling pins. They then proceed to knock her down with Kryptonite bowling balls. Eventually, Supergirl is able to free herself. She then turns the Toymaster's toys against him. After defeating the villains, Supergirl sends the Black Flame back to Kandor. The other three villains are placed into a ship and towed into space, supposedly toward the Phantom Zone.