Complex sentence: Watched over by the well-armed Wyatt and his posse, Virgil and Allie had dinner in Tucson at Porter's Hotel, then reboarded the train, watched over by Wyatt and the others.
Split into simpler sentences: Watched over by the well-armed Wyatt and his posse, Virgil and Allie had dinner in Tucson at Porter's Hotel. That night, Virgil and Allie had dinner at Porter's Hotel in Tucson, then reboarded the train, watched over by Wyatt and the others.