The Eagle and The Dragon: A Novel of Rome and China is my current work in progress, a full-length historical fiction framed by two historical events: the Gan Ying expedition to Rome in 97AD, and a relationship between the two empires firm enough for Rome to propose an alliance in 166AD between the two countries against Rome's arch-enemy Parthia, though nothing came of that effort. Between those two events would have been the first Roman mission to China. That story is lost to us, but perhaps it went something like this:
When Senator and Indian Ocean shipping magnate Aulus Aemilius Galba is tapped by Emperor Trajan to lead the first Roman mission to Hanaean China, he anticipates an easy path to fame and fortune. He outfits a convoy of a new class of merchant ships to make the long voyage from the Red Sea to China, and selects his cousin Gaius Lucullus, a senior Roman officer, and the centurion Antonius Aristides, to accompany him on this mission. His mission quickly attracts attention of the worst sort., but despite being beset by storms and pirates, his ships reach China after almost a year at sea. Trouble lurks in the Hanaean capital where the Parthian ambassador seeks to sabotage Rome's attempt to establish a relationship with the Hanaean emperor. Senator Galba must ultimately risk death of his whole party to uphold Roman honor. Help comes from an unexpected quarter, and he and his party, with the beautiful Marcia Lucia, escape. They must fight their way back to Rome through the territory of the wild Xiongnu north of the Yellow River and across the Pamir Mountains into Bactria, before crossing hostile Parthia. On their return, they find their mission has succeeded far better than they had ever expected.