After having an emotional moment together where they chose not to reject Zane and instead strive towards finding a cure to his current condition. Zane returned back to Gravestone, and the bunker complex which he and the others lived within.
Needless to say, after suffering a near and total mental breakdown earlier in the day, Zane was in no mood to take part in the festivities that were commonly celebrated after achieving a great victory by the group. Instead, he cleaned himself up and only marginally ate the meal that was prepared for the group in an attempt to maintain some sense of normalcy despite his new condition.
Despite his physical transformation into the very enemy which they sought to destroy, nothing had really changed with Zane, and his lot in life. He was still the leader of Gravestone, and still maintained a familial relationship with Elena and the others.