2020’s Critical Point is a third volume in S. L. Huang’s Russell’s Attic series.
If Cassandra “Cas” Russell were a member of the Legion of Super-Heroes, the little placard in front of her seat would read “Super-Mathematics.” Cas can perform and apply hypercomplex mental calculations at stupendous speed, a talent that she applies to everything from simple bookkeeping to acrobatics.
What Cas doesn’t have is a moral compass. She’s working hard to develop a functional substitute because she craves human contact. Not being an amoral monster appears to be a crucial step towards maintaining her rudimentary social life.
Her friends may need the monster in Cas.