| Issue | #12 |
| Published | November 1987 |
| Frequency | monthly |
| Cover Price | 1.75 USD; 2.50 CAD |
| Pages | 36 |
| Editing | Randy Stradley |
| Characters | Concrete; Portheus Principle (inset); Masque [The Mask] (inset) |
| Genre | science fiction |
| Pencils | Paul Chadwick |
| Inks | Paul Chadwick |
| Characters | Concrete |
| Genre | science fiction |
| Script | Paul Chadwick |
| Pencils | Paul Chadwick |
| Inks | Paul Chadwick |
| Letters | Bill Spicer |
| Reprinted | in Concrete (Dark Horse, 2005 series) #3 (January 2006) |
| Script | Mark A. Nelson |
| Pencils | Mark A. Nelson |
| Inks | Mark A. Nelson |
| Characters | Masque [The Mask] |
| Script | Mark Badger |
| Pencils | Mark Badger |
| Inks | Mark Badger |
| Letters | Tim Harkins |