Medusa. The Realm Series, #5

Tartarus has shifted the balance of power. Lady Vermont's treachery has armed the queen with an alliance that threatens humanity's greatest achievement-the interstellar gate, Medusa. If the queen succeeds, the war for Earth's survival may be over before it begins. Unaware of the danger to her home, Emmeline faces her next challenge-the mythical device, Archanexes, has triggered unknown mutations in her DNA.
To complete her quest for revenge Argon's death, Emmeline must master its dangerous power before it destroys her-and everything she fights for. Anastasia has sacrificed everything to free Titan and Prometheus, forging an alliance with the Valtorians and acquiring technology that could take Earth's ships home faster than ever. But this victory tastes hollow in the wake of Aurora's destruction, corruption spreading through Imperial Command, and the looming threat to Medusa.
Now she must make an impossible choice: confront the queen's forces to protect Medusa or race back to Earth to join the fleet. As destinies intermingle, one wrong step could shatter everything. Will Lady Vermont's treachery doom humanity? Can Emmeline control the power within her? And will Anastasia's gambit tip the scales-or seal Earth's fate? As fates collide, who will turn to stone under Medusa's gaze?