Catherine Halsey's personal journal (Earth-5162)

Catherine Halsey's personal journal was a journal belonging to Dr. Catherine Halsey, where she detailed her thoughts and discoveries, from 2510 to 2552, a period of forty two years.

History
The journal was bought by Dr. Catherine Halsey in a shop at Reach on August 2510. For the next four decades, she kept the journal close to her, documenting her extensive research to counter the threat of the Insurrectionists, and later, the Covenant.