In his notebook, quantum physicist Anton Zeilinger provides insight into a crucial phase of his scientific research. It features excerpts from his personal notebooks from March to June, 1993-a time in which he undertook early experiments with multiphoton states and entangled photons. The key terms for this emerging quantum-information technology were quantum computation, quantum communication, quantum cryptography, quantum cloning, and quantum teleportation. Zeilinger offers us a view of what is likely the first sketch of the teleportation scheme, notations of multiports and entanglements between two photons in higher-dimensional Hilbert spaces. For non-experts in this field, Zeilinger's solid introduction, and his drawings, codes, and calculations, open a door to a world. Anton Zeilinger (*1945) is Professor of Physics at the University of Vienna and Director of the Institute for Quantum Optics and Quantum Information at the Austrian Academy of Science; he is a member of the Honorary Advisory Committee of dOCUMENTA (13).