Caleb arrived in Sunnydale and non-fatally stabbed Shannon, telling her to give Buffy the message that "I have something of yours" in order to lure her into a trap. After following a Bringer to the Vineyard, Buffy and her forces attacked.
Buffy and her forces arrived and engaged several Bringers. The group held them off easily before Caleb called them off in order to fight himself. After speaking with Buffy, Caleb knocked her out with a single powerful punch, displaying his own incredible strength.
Caleb engaged the Potentials and Scoobies with the Bringers joining in a bit. Caleb was able to easily fend off both Spike and Faith and broke Rona's arm when she tried to fight him. Caleb also broke a Potential's neck and stabbed Molly, killing both before Buffy recovered and ordered a retreat.
Buffy engaged Caleb and managed to knock him down, allowing most of the group to escape, but Caleb grabbed Xander and gouged out his left eye with his thumb. Spike rammed him to the ground, allowing him and Buffy to escape with Xander. Caleb recovered quickly, but let the group go as he had won.
Buffy and her forces became greatly demoralized as a result of this battle and Caleb's incredible power. Caleb's presence in Sunnydale gave the First a major advantage due to his incredible strength and power. Also, the battle weakened Buffy's leadership in the eyes of her group and they eventually mutinied against her and forced her to leave.