The stunning conclusion to the Star Trek: Hidden Frontier series.

The Station is under siege by the Grey once more, as the crew of the USS Helena struggle to catch Siroc before he arrives at the Dyson Sphere. While the battle rages outside, Shelby and Lefler are leading a skeleton crew of 93 in a desperate ploy to restore the USS Excelsior and rejoin the fight to protect the station's civilians.

With time completely gone, all hope lies in Admiral Knapp, Martinez, Jorian (Zen) Dao, Corey Aster and Jenna McFarland being able to figure out how to use the Hybrid ship; but things are far more different - and deadly - than they seem.

With Ro as their captive and unwilling source of the technical data needed, Siroc and Betras arrive on the Dyson Sphere, and Siroc will stop at nothing to get to the secrets of the Dyson Sphere. Tolian Naros, along with Faisal, Henglaar, Elbrey, and others also arrive to try to rescue Ro Nevin and stop Siroc from bringing on the potential destruction of the universe.