| Issue | #2 |
| Published | May 1940 |
| Cover Price | 0.10 USD |
| Pages | 68 |
| Editing | Ned Pines |
| Characters | Ted Crane |
| Pencils | L. North |
| Inks | L. North |
| Characters | Ted Crane (first appearance); Prof. Hawkins (first appearance); Betty Hawkins (first appearance); The Leopard Men (first appearance; villains); Bullard (first appearance; villain) |
| Pencils | George Mandel |
| Inks | George Mandel |
| Characters | Ted Hunt (first appearance); Jane Martin (first appearance); Dr. Matthew Martin (first appearance); Mercurian cave-people (first appearance); Flaedo (first appearance; villain; death); Zado (first appearance; villain); King of Thian (first appearance; villain); Otto (first appearance; villain); another spy (first appearance; villain) |
| Pencils | Max Plaisted |
| Inks | Max Plaisted |
| Characters | Dr. John Thesson [the modern Theseus] (first appearance; origin); Theseus (first appearance); Ariadne (first appearance); Aegeus (first appearance); Minos (first appearance; flashback); Prof. Craig (first appearance); Perphetes (first appearance; villain; death; flashback); Sinis (first appearance; villain; death; flashback); Minotaur (first appearance; villain; death; flashback); Procostous [Procrustes] (first appearance; villain); Cercion (first appearance; villain; death) |
| Script | George Mandel |
| Pencils | George Mandel |
| Inks | George Mandel |
| Colors | George Mandel |
| Characters | Dan Williams; Patricia Knowles (first appearance); Edward Knowles (first appearance; villain; death) |
| Pencils | Ray Lowry |
| Inks | Ray Lowry |
| Characters | Sgt. Bill King; Nazis (villains) |
| Pencils | Leonard Sansone |
| Inks | Leonard Sansone |
| Script | Jackson Cole |
| Letters | typeset |
| Characters | The Masked Rider (first appearance; only appearance); The Specter [Jim Sanford] (first appearance; villain) |
| Characters | The Sphinx [Ellsworth Forrester] (first appearance); Marjorie Grover (first appearance); Thomsen (first appearance; villain); Saunders (first appearance; villain); other spies (first appearance; villains) |
| Pencils | Kin Platt? |
| Inks | Kin Platt? |
| Script | Donald Bayne Hobart |
| Letters | typeset |
| Characters | The Mask [Tony Colby]; Olly Snate (villain; death); Otto Fox (first appearance; villain; death) |
| Pencils | Raymond Thayer |
| Inks | Raymond Thayer |