- "At the dawn of time, the Monitor placed quantum towers on key Earths as a last line of defense. The red skies are dissipating, which means it's working."
"From this design it looks like the tower is capable of generating a quantum-flux field; which could, theoretically—"
"Reverse the exogenic state of the antimatter wave; thereby, dissipating the antimatter energy."
- —Harbinger, Querl Dox and Ray Palmer on the quantum towers' purpose[src]
On December 10, 2019, the one buried on Earth-38, underneath National City, rose above the surface, fending off the antimatter wave approaching the planet. It somewhat worked, but after an army of shadow demons attacked, it began to break down. Supergirl and Superman began using their heat vision to solar charge the tower's panels, but it simply slowed the wave down. Ultimately the shadow demons were too much, causing the antimatter to destroy Earth-38.