Sage is a mutant with a computer-like mind. She can calculate probabilities and "store" data, giving her an eidetic-like memory. The arrangement of her mind makes her proof against most telep[athic probes.
Initially a member of the Underground, Sage joins the Inner Circle when the group schisms. She serves loyalty with the Inner Circle, but when Lorna uses her access to check security footage, Reeva assumes that Sage betrayed the Inner Circle and kills her.