| Issue | #23 |
| Published | January 2008 [November 21, 2007] |
| Cover Price | 2.99 USD; 3.65 CAD |
| Pages | 36 |
| Editing | Mike Carlin; Elisabeth V. Gehrlein (assistant) |
| Characters | Superman-Prime [Clark Kent]; Mr. Mxyzptlk |
| Genre | Superhero |
| Pencils | J.G. Jones (signed) |
| Inks | J.G. Jones (signed) |
| Colors | Alex Sinclair [signed as Sinc] |
| Characters | Mary Marvel [Mary Batson]; VILLAINS: Superman-Prime [Clark Kent]; Mr. Mxyzptlk; Annataz Arataz (Earth-3's Zatanna Zatara; dies); Eclipso [Jean Loring]; Dominators; Ultraman; Lord Havok |
| Synopsis | Superman-Prime tortures Mr. Myxzptlk, trying to get help in finding his Earth. Lord Havok destroys a Dominion fleet. |
| Genre | Superhero |
| Script | Paul Dini; Keith Giffen (story consultant) |
| Pencils | Tom Derenick |
| Inks | Wayne Faucher |
| Colors | Pete Pantazis |
| Letters | Ken Lopez |
| Characters | Mr. Mxyzptlk (origin); Superman [Clark Kent; Kal-El]; Lex Luthor |
| Synopsis | The origin of Mr. Mxyzptlk. |
| Genre | Superhero |
| Script | Scott Beatty |
| Pencils | Kyle Baker |
| Inks | Kyle Baker |
| Colors | Kyle Baker |
| Letters | Ken Lopez |
| Editing | Elisabeth V. Gehrlein |
| Characters | Power Girl; Superman [Clark Kent; Kal-El]; Flash [Jay Garrick]; Green Lantern [Kyle Rayner]; Jakeem Thunder; Flash [Wally West]; Wonder Woman |
| Script | Dan Didio |
| Pencils | Carlos Pacheco (signed) |
| Inks | Jesus Marino (signed) |
| Colors | J.D. Mettler |
| Letters | typeset |
| Notes | Dan Didio wishes everyone a Happy Thanksgiving and gives a few clues about upcoming DCU events. Hot list - COUNTDOWN #23, COUNTDOWN PRESENTS: THE SEARCH FOR RAY PALMER: GOTHAM BY GASLIGHT #1 and JUSTICE LEAGUE OF AMERICA #15. House ad for COUNTDOWN #22. |
| Reprinted | from JSA (DC, 1999 series) #54 (January 2004) [upper portion of cover] |