All Our Tomorrows: Riven Worlds Book Four

War has come to Concord. Now no one and nowhere is safe.
When indestructible warships and dimension-tearing weapons are not enough to defeat the enemy, how do you protect thousands of worlds and trillions of citizens from a Rasu tidal wave bent on devouring everything in its path?
The Rift Bubbles offer much-sought protection, but is the safety they promise anything more than an illusion? A weapon crafted by the nearly extinct Ourankeli may hold the key to gaining the upper hand—or it may be...