An examination of some more advanced concepts of quantum mechanics, focusing on describing Dirac's bra-ket formulation of quantum theory. I discuss the formulation of quantum mechanics in terms of vectors in Hilbert spaces, Hermitian operators as corresponding to observables, orthogonality of eigenstates, incompatible observables, and Schrodinger's equation. Recommeded pre-listening is Episode 14: Principles of Quantum Mechanics.