The Shrike Tower was a vertical concretion of massive crystalline spikes created by the Shrike when they infected enough hosts, enabling them to significantly multiply their number to invade a planet.
During her quest to reclaim the Di'Allas, Izel created the Shrike to invade planets. The Shrike infected hosts and took control of their bodies, directing them to convergence points of the planet's Ley lines. From there, all the hosts would get torn apart by the Shrike manifesting massive mineral protrusions out of their bodies, building them into a tower which Izel used as a beacon to arrive on the planet. Once the tower drew enough energy from the planet, it would burst out and create even more Shrike which soon took over the entire population until the planet's energy ran dry, destroying the planet.
Earth was the last planet invaded by the Shrike sent by Izel. Despite the combined efforts of Sarge's Squad and S.H.I.E.L.D. to find and contain the Shrike hosts, there were largely enough hosts left for them to gather in a desert area and begin to form a Shrike tower, destroying the bodies of several Humans in the process. The formation of this tower was witnessed from afar by Sarge, Daisy Johnson and Melinda May, who in turn alerted Alphonso Mackenzie. Meanwhile, in the Lazy Comet approaching Earth, Izel spotted the tower and directed her spaceship towards it.
In an attempt to destroy the tower and exterminate both the Shrike and Izel, Sarge locked his truck's trajectory onto the tower and armed an Atom Bomb, hoping that the impact of the truck on the tower would detonate the bomb, thus blasting everything in a wide radius. Having been told about this plan which would kill them, Johnson, May, Deke Shaw and Snowflake looked for and found the bomb. Using her powers, Johnson protected it from the impact.
As a result, the truck did indeed smash the base of the tower, thus triggering its complete collapse before it could reach an extreme height and empty the energy of the Earth. Still, the tower unleashed a massive swarm of new Shrike when it was destroyed, forcing S.H.I.E.L.D. to exterminate them all thanks to Quake's superhuman abilities. Having witnessed the destruction of her tower, Izel ordered the Lazy Comet to remain in the upper atmosphere until she was contacted by Sarge, who revealed that he had masterminded the destruction of the tower, although he had enraged that the bomb did not detonate.