Treatise on the Outer Planes
Light, Shadow, Chaos, Order: Treatise on the Outer Planes is a dangerous volume that outlines methods for contacting powerful beings outside of the Material Plane. It also describes the primary plane and several demiplanes of each force in its title. The book grants a +4 circumstance bonus to Knowledge (Planes) checks when researching information about planes of light, shadow, chaos or law.
You found a copy of Light, Shadow, Chaos, Order: Treatise on the Outer Planes among the belongings of the late leader of the Seravash tribe of lizardfolk . From the shaman’s notes, it is clear he used the tome to first communicate with Shurensha.