"Gem Drill" is the second episode of the third season of American animated television series Steven Universe, which premiered on May 12, 2016 on Cartoon Network.

Picking up immediately after the events of "Super Watermelon Island", with the other Crystal Gems stranded on Mask Island, Steven (Zach Callison) tells Peridot (Shelby Rabara) that it is up to the two of them to stop the Cluster, the underground geo-weapon that threatens to destroy the Earth.

When Cluster prototypes—artificial, deformed fusions of broken Gem shards buried in the Earth—attack the drill, Steven fights them off but feels uneasy about not trying to help them.

The drill eventually arrives at the Cluster, an immense spherical formation of millions of Gem shards.

Rendered unconscious by the resulting ordeal, Steven experiences a vision of himself floating among the shards of the Cluster.

The episode was written and storyboarded by Raven Molisee and Paul Vileco and directed by Ki-Yong Bae and Jin-Hee Park (animation), Jasmin Lai (art), Kat Morris (supervising) and Ian Jones-Quartey (co-executive producer).