In The Multiversity Guidebook, writer Grant Morrison and various artists outline the 52 different Earths — each located in its respective parallel universe — that comprise DC Comics’ narrative “Multiverse”; for example, Earth-0 is the home for current versions of DC’s heroes (Superman, Wonder Woman, etc.), Earth-3 is dominated by the heroes’ villainous doppelgangers, Earth-43 is a world of super-vampires, and so on. As explained by the guidebook, these parallel universes are separated from each other by a unique vibrational frequency.

But the guidebook does not identify all 52 Earths. Seven “unknown worlds” — Earth-14, Earth-24, Earth-25, Earth-27, Earth-28, Earth-46, and Earth-49 — are identified as being created “by an Inner Chamber of 7 Monitor Magi for a mysterious purpose.” The “Monitor Magi” are a reference to the Monitors, powerful alien beings who observe the Multiverse, but the nature of these seven unknown worlds and their “mysterious purpose” are unrevealed.

From THE MULTIVERSITY GUIDEBOOK — the entry for Earth-25

But in issue seven of The Terrifics, the creative team of artist Dale Eaglesham and writer Jeff Lemire subtly identify the mysterious Earth-25 as the home of characters originally published under DC’s defunct America’s Best Comics imprint. Established in 2009 by writer Alan Moore, the imprint featured such heroes as the pulp-inspired scientist adventurer Tom Strong, the mystical Promethea, and the masked detective Greyshirt, among others, before its cancellation.

Tom Strong is foremost among the characters appearing in this cover image for ALAN MOORE”S AMERICA’S BEST COMICS

These characters were not part of DC’s narrative continuity; that is, the America’s Best Comics characters did not interact with non-imprint DC characters or events. However, in 2018, DC introduced Promethea in Justice League of America #23, the first time a character from the imprint appeared in an in-continuity story.

Later, in the first issue of The Terrifics, the comic’s protagonists discover a holographic distress message from Tom Strong. However, the appearance of both Promethea and Strong in DC continuity did not link the characters to one of the specified 52 Earths. But in The Terrifics #7, in one panel, the hero Mr. Terrific reveals that he has identified Strong’s home dimension as “vibrating on a frequency 25 wavelengths from our own.” [Significantly, the emphasis (in bold) of the number “25” is made by the creative team.]

From THE TERRIFICS #7; art by Dale Eaglesham; colors by Mike Atiyeh

Because the comic’s protagonists live on Earth-0, and the parallel worlds are separated by vibrational frequencies, Mr. Terrific’s assertion that Strong’s dimension is “25 wavelengths” from Earth-0 provides subtle but clear confirmation that Tom Strong lives on the mysterious Earth-25. Whether other America’s Best Comics heroes (such as Promethea and Greyshirt) live on this world is unknown, although Strong’s supporting cast (villain Paul Saveen, robot Pneuman, wife Dhalua) are seen on Earth-25 in issue seven.

The Terrifics #7 reveals a missing piece of DC’s cosmography. This revelation is handled by the creative team in a subtle manner, and it remains unclear whether DC will introduce other America’s Best Comics characters to its continuity via Earth-25, or what “mysterious purpose” the Monitors — and DC Comics — have in mind for Tom Strong’s world.