| 0 | - | cover | 1 | pencils: Howard Purcell; inks: Howard Purcell | The Spectre [Jim Corrigan]; The Flash [Jay Garrick]; Green Lantern [Alan Scott] |
| 1 | - | public service announcement | 1 | script: Eleanor Roosevelt | |
| 2 | The Mysterious Mister X, Introduction | comic story | 3 | script: Gardner Fox; pencils: E. E. Hibbard; inks: E. E. Hibbard | Justice Society of America [The Hourman [Rex Tyler]; Dr. Fate [Kent Nelson]; The Flash [Jay Garrick]; Green Lantern [Alan Scott]; The Sandman [Wesley Dodds]; The Atom [Al Pratt]; Hawkman [Carter Hall]; The Spectre [Jim Corrigan]]; Mr. X (villain, racketeer); Mr. X's gang (villains) |
| 3 | The Mysterious Mister X, Chapter 1 | comic story | 7 | script: Gardner Fox; pencils: Hal Sharp; inks: Hal Sharp | The Flash [Jay Garrick]; un-named Fire Department Captain; un-named City Mayor; Johnny; Mr. X (villain); Flame Farmer (villain); Mr. X's arson racketeers (villains) |
| 4 | Here It Is - Boys and Girls All-Flash Quarterly No. 1! | promo (ad from the publisher) | 1 | pencils: E. E. Hibbard; inks: E. E. Hibbard | The Flash [Jay Garrick] |
| 5 | The Mysterious Mister X, Chapter 2 | comic story | 6 | script: Gardner Fox; pencils: Cliff Young; inks: Cliff Young | The Sandman [Wesley Dodds]; Dian Belmont; Mr. X (villain, cameo); the Kidnapper's Union [Gentle Grady; others un-named] (villains) |
| 6 | The Mysterious Mister X, Chapter 3 | comic story | 7 | script: Gardner Fox; pencils: Sheldon Moldoff; inks: Sheldon Moldoff | Hawkman [Cater Hall]; Hawkgirl [Shiera Sanders]; Mr. X (villain, cameo); Masie (villain); un-named lawyer (villain); Wing Norris (villain); Norris' gang of jewel thieves (villains) |
| 7 | The Mysterious Mister X, Chapter 4 | comic story | 6 | script: Gardner Fox; pencils: Howard Sherman; inks: Howard Sherman; letters: Howard Sherman | Dr. Fate [Kent Nelson]; Inza Cramer; Vera Ross; Mr. X (villain, cameo); Magico (villain, magician, reforms); Magico's henchmen (villains) |
| 8 | - | in-house column | 1 | pencils: Jon L. Blummer; inks: Jon L. Blummer | Hop Harrigan |
| 9 | - | promo (ad from the publisher) | 2 | pencils: various; inks: various; letters: typeset | Batman [Bruce Wayne]; Robin [Dick Grayson]; Superman [Clark Kent]; Green Lantern [Alan Scott]; Doiby Dickles; Dr. Fate [Kent Nelson]; The Spectre [Jim Corrigan]; Starman [Ted Knight] |
| 10 | The Mysterious Mister X, Chapter 5 | comic story | 6 | script: Gardner Fox; pencils: Bernard Baily; inks: Bernard Baily; letters: Bernard Baily | The Hour-Man [Rex Tyler]; Clancy (Policeman); un-named Commissioner of Police; Mr. X (villain, cameo); phony Hour-Man (villain); "Monkey" Macy (villain); Macy's gang (villains) |
| 11 | The Mysterious Mister X, Chapter 6 | comic story | 6 | script: Gardner Fox; pencils: Ben Flinton; inks: Ben Flinton | The Atom [Al Pratt]; Mr. X (villain, cameo); Muscles (villain, reforms); Muscle's Men [Butch; Crusher; Bloody; Smasher; Slug] (villains, all reform) |
| 12 | Johnny on the Spot | text story | 1.5 | script: Evelyn Gaines; pencils: Sheldon Mayer; inks: Sheldon Mayer | Johnny Thunder; Herman Darling; Daisy Darling; Joe the Butcher (villain); Small Change (villain) |
| 13 | - | promo (ad from the publisher) | 0.5 | | Mutt; Jeff |
| 14 | The Mysterious Mister X, Chapter 7 | comic story | 7 | script: Gardner Fox; pencils: Bernard Baily; inks: Bernard Baily; letters: Bernard Baily | The Spectre [Jim Corrigan]; Enrico; Enrico's un-named wife; un-named Police officer; un-named Chief of Police; Mr. X (villain, cameo); Mr. X's gang of gamblers [Baretti; rest un-named] (villains) |
| 15 | The Mysterious Mister X, Chapter 8 | comic story | 7 | script: Gardner Fox; pencils: Irwin Hasen; inks: Irwin Hasen | The Green Lantern [Alan Scott]; un-named City officials; un-named newspaper editor; Mr. X (villain, cameo); The Professor (villain); Professor's gang (villains) |
| 16 | The Mysterious Mister X, Conclusion | comic story | 2 | script: Gardner Fox; pencils: E. E. Hibbard; inks: E. E. Hibbard | Justice Society of America [The Flash [Jay Garrick]; Hawkman [Carter Hall]; The Atom [Al Pratt]; The Spectre [Jim Corrigan]; Dr. Fate [Kent Nelson]; The Sandman [Wesley Dodds]; The Hourman [Rex Tyler]]; un-named Police Sergeant; Mr. X (villain) |
| 17 | - | promo (ad from the publisher) | 1 | pencils: E. E. Hibbard; inks: E. E. Hibbard | Justice Society of America [The Hourman [Rex Tyler]; Docxtor Fate [Kent Nelson]; The Flash [Jay Garrick]; Green Lantern [Alan Scott]; The Sandman [Wesley Dodds]; The Hawkman [Carter Hall]; The Atom [Al Pratt]; The Spectre [Jim Corrigan]] |