The Journeyman Historical Log disc is a compilation of news articles and historical accounts chronicling all of known history. Each day, all news stories worldwide are automatically collected at the Temporal Security Annex, and two new historical logs are pressed: One remains in the historical log computer of the Temporal Security Annex, and the other is brought back 200 million years in the past, where it is stored as a security measure; it is accessible with the Journeyman Key.
If history should be deliberately changed, the disc which has been placed in the distant past will not be updated with the new version of history, as it exists at a point in time prior to any probable change. The disc which is still at the Temporal Security Annex, on the other hand, will be updated with the altered version of history. Therefore, if a rip in time is detected, the agent on duty can recover the log which has been placed in the past as a source of unaltered historical information.
Once the agent has returned to the Temporal Security Annex with the accurate log disc and has inserted it into the empty historical log drive, the computer will compare it to the Journeyman log disc which was left in the present and subsequently altered. By cross referencing the date of the rip to the discrepancies found between the two logs, the computer will be able to isolate the changed event. A computer-generated persona will then read the correct and altered versions of this event to the agent.