After the final battle with Zion's White Legs, which would lead to their defeat and the death of their savage leader, Joshua Graham would remain in the canyon with his tribe, the Dead Horses, alongside their Sorrow neighbors.
The lone surviving Happy Trails assistant, a courier, who had helped them in winning their war left the canyon after all was said and done. Not permanently, of course; he kept close affiliations with Joshua and the Zion tribes after his departure. He would even return on occasion, though this would become something of great scarcity as months passed. With the canyon now restored to its rightful neutrality, the courier absent more often than not, and the White Legs no longer a concern, Joshua had the opportunity to set his priorities onto other matters.
Such as the Legionary couriers Dead Horse scouts would report traveling Zion's beaten roads time and time again. The Dead Horses would never attack the Legionaries, despite knowledge of their chief's resentment for them, as these Legionaries would pass through as quickly and silently as they came. No aggression. No crucifixion. No preaching. Not a word spoken, in fact. The passing couriers always seemed to be more intent on their job at hand than the Caesar-less tribals taking up residence within the canyon. …A rare occurrence for the imperialistic Legion.
In the most recent months, the sightings of these couriers became subtly more common. Just enough so to raise Joshua's suspicion regarding these Legion men's true reason for navigating Zion.
The Legion had very few camps and even less people of interest on the opposing treks of land beyond Zion. For what reason were they sending such a significant amount of their men through this particular path? Taking all things into consideration, Joshua evidently became concerned these couriers may be within the handful of Caesar's personal spies, sent to collect reports of Joshua's whereabouts; perhaps so that Caesar could get himself an upper hand in his pursuit to have Joshua assassinated. A long time goal the tyrant still had yet to accomplish.
And we all know how much Caesar loves failure, don't we? Per example, Legate Joshua Graham's "service discharge".
In all of Caesar's years of trying and failing to kill the infamous Burned Man, this would be his most creative, devious attempt yet. Sending non-hostile men through the canyon, posing as harmless couriers, and giving them no direct evidence to reveal their identity as Frumentarii. He knew Joshua could not kill who he had no rightful reason to. Was it that Caesar was finally using that knowledge to his advantage?
Perhaps, if these couriers could not be killed, they could be caught. The trek from Zion back to The Fort was a long, dangerous one; one which often undertook delays due to the Mojave's fearsome environment. That in mind, it is also true the vast majority of travelers coming through Zion would pass their expected date to return. Assuming they did make it home. Unfortunately, the option of killing a courier and posing death by natural causes was off the table for Graham. Caesar trained his men better, they both knew that. He would detect tribal interference the moment word of his dead courier passed. Joshua could, however, take advantage of a delay in the live courier's arrival; stage the Legionary returning to camp a week later than intended due to "violent dust storms" throughout the canyon.
Accomplishing such a goal as discretely capturing a Legionary was something Joshua and his unfortunately ignorant tribe could not do alone. Especially in the case these couriers proved to truly be Frumentarii, which were indisputably some of the most deadly men under Caesar's reign.
Joshua would require the aid of a… off-kilter friend. Someone he knew would offer the right assistance, as well as trust. Perhaps not quite as much of a stable trust as Joshua would like, but, nevertheless, there were very few other than him he trusted more.
The Courier.