Claws That Catch - John Ringo, Travis S Taylor

The story so far:- An accidental explosion opened a discontinuity in the fabric of space that let a predatory life form invade Earth. Mankind was able to close the portal, with the help of another species who were also under threat by the predators.These predators are called Dreen. Having sealed direct access, it became necessary to try and find if the Dreen could attack Earth through normal space. In the course of exploration other alien species were encountered, some actually fleeing the Dreen. Now, using some alien technologies begged, borrowed or stolen from ruins, Mankind is again looking ... more