In an attempt to get a leg up on the competing ranches in the area, Miss Charlotte Castle secretly ordered a large item from Smith and Robards. To keep the matter as private as possible, she had the item shipped to Santa Fe, New Mexico, and looked to outside help to deliver it to the ranch.
Arriving at the Rocking C Ranch, Miss Castle's newest wrangler, and friend to many of the posse, Darnell Buchanan, informed the group of Miss Castle's intentions. They were to complete the one week ride to Santa Fe, receive the package, and link up with a freelance steam wagon cargo transporter she had hired to haul the crate the item would be in, then escort the driver and crate back to the ranch intact.
Once in Santa Fe, the posse, consisting of the then acting sheriff Jackson Tanning, deputy sheriff Lily Mayfair, John Newcomb, Pauline Hall, and newcomer by the name of Alexander Tithes, approached the Lone Star station foreman, only to find another man, whom they later came to know as Rollins, arguing that he needed to take the crate immediately.
After long argument, in which Rollins produced a bill of sale (determined to be possibly counterfeit) to match the telegraphed receipt Miss Castle gave to the escorts, the tiff was finally settled when a man wearing a driving cap, scarf, goggles, and a long driving coat came up to claim the crate for the Rocking C. Having now met the steam wagon driver, a cheerful man named Simon Hapworth, known to friends as "Happy", the posse then had to wait until the next morning, as the storage yard access was closing for the day.
Happy treated the posse to drinks and purchased spare stays at his hotel for his new friends. During this time, Tanning and Mayfair traveled to the territorial penitentiary, looking for information on some executions that took place several weeks prior. Rejoining the rest of the group, they all turned in for the night.
In the morning, they finally load up the crate, hearing from the station master that someone indeed tried to break into the warehouse, but the attempt was thwarted by night guards. On the road, a few days passed with little trouble, until on the third day a Rattler burst forth from the ground, chasing the posse and claiming Alexander Tithes' horse as the dish of the day. With the creature apparently satisfied with its meal, the crew was back on the trail.
Just outside of the Rocking C Ranch, however, a wagon with a missing wheel blocked the only clear path. The posse halted, and Happy eagerly rushed to help, noticing too late that the wheel had been manually removed. One of the ambushers shot him, killing him instantly. A fight ensued, with concealed riflemen firing down on the group from cover. With their array of abilities, and fueled by anger over their new friend's sudden demise, easily dispatched the majority of the half dozen attackers, taking the two leaders prisoner and escorting them to jail.
Despite the tragedy, the crew successfully delivered the crate to the ranch, where it was unveiled as a brand new S&R Flapjack Machine.
Tanning and Otto returned to claim Happy's now ownerless steam wagon, and Pauline, especially stricken by Happy's death, took the time to bury him and say a few words over his grave, keeping his hat and goggles as mementos.
Questioning of the two surviving brigands revealed that they had been hired to ambush them, but did not know by whom.
Miss Castle paid the posse their due, splitting up Happy's share among them, along with the split between the money the ambushers had on them at the time and the pawning of any leftover valuables.