The Lives And Times Of Dan, Part II

If Dan always returned from the pre-stellar past to timeline (i), then he would not know of other timelines and would have no reason to apply the numeral, (i).

If he returned from the past to Deirdre's home timeline, then he would be able to join Patrol agents at the lodge or the Academy and to help with the intervention in the Second Punic War. However, he would need to know when to arrive at the lodge or the Academy. Otherwise, he would merely be disturbing agents who knew nothing of the temporal alteration.

If Dan never travelled into the past but remained permanently in the Danellian era, then he would not know of any alternative timelines.

The Danellians must found the Patrol because they want to ensure that they will always be free to travel into the past and then to return to their home era.