Unnecessary But Quality
Danger Girl is pretty well established, but in an attempt to reach new fans, DC released a teaser zero numbered issue of Danger Girl in digital format.
Story-wise, it's totally unnecessary (as with most zero numbered issues), and takes place immediately before the events of Danger Girl no.1. By immediately, I mean immediately - Abby Chase is being held prisoner by Donavin Conrad. She manages to make escape along with the golden skull. What follows is, of course, a chase (get it?). All the elements are introduced - humor, action, cheesecake, and homages to Indiana Jones and James Bond.
It may be unnecessary - but it's quality unnecessary.