Preface; Acknowledgements; Part I. From Philosophy to Physics: The years that left nothing unaffected; 1. The appeal of ideas; 2. Goëthe as a scientist; 3. How absolute is our knowledge?; 4. How do we come to know things?; 5. London's teachers in philosophy; 6. Husserl's teachings; 7. Expectations of things to come; 8. The thesis in philosophy; 9. Tolman's principle of similitude; 10. The necessary clarifications; 11. Work on quantum theory; 12. Transformation theory; 13. Unsuccessful attempts at unification; Part II. The Years in Berlin and the Beginnings of Quantum Chemistry: The mysterious bond; 14. London in Zürich; 15. Binding forces; 16. The Pauli principle; 17. Reactions to the Heitler-London paper; 18. Polyelectronic molecules and the application of group theory to problems of chemical valence; 19. Chemists as physicists?; 20. London's first contacts in Berlin; 21. Marriage; 22. Job offers; 23. Intermolecular forces; 24. The book which could not be written; 25. Leningrad and Rome; 26. Difficulties with group theory; 27. Linus Pauling's resonance structures; 28. Robert Mulliken's molecular orbitals; Part III. Oxford and Superconductivity: The rise of the Nazis; 29. Going to Oxford; 30. Lindemann, Simon and Heinz London; 31. Electricity in the very cold; 32. The end of old certainties; 33. The thermodynamic treatment; 34. The theory of Fritz and Heinz London; 35. Initial reactions by von Laue; 36. The discussion at the Royal Society; 37. Termination of the ICI fellowship; Part IV. Paris and Superfluidity: The Front Populaire; 38. The article in Nature 1937 and 'Nouvelle Conception'; 39. Laue again; 40. The structure of solid helium; 41. The peculiar properties of helium; 42. Bose-Einstein condensation; 43. The note in Nature; 44. The two-fluid model; 45. The trip to Jerusalem; 46. Leaving again; 47. The observer in quantum mechanics; Part V. United States and the Typing up of Loose Ends: Duke University, North Carolina; 48. The Soviet Union, Kapitza and Landau; 49. The war years; 50. The 1946 Cambridge Conference; Unsettled and unsettling issues in superfluidity and superconductivity; 51. Heisenberg's theory and London's program for a microscopic theory; 52. More problems with Laue; Hopeful signs from helium-3; 53. 'Second sound' at very low temperatures; 54. Writing Superfluids; 55. The trip to Europe; 56. Some developments in superconductivity; 57. An ugly finale; 58. Could Landau be right?; 59. The worrisome realities of the post-war era; 60. The second volume of Superfluids; 61. William Fairbank; 62. Further developments; 63. The Lorentz Model; 64. Consultantship at Los Alamos and the interview for security clearance; 65. The last days; List of publications of Fritz London; Bibliography.