One of the features of a sandbox campaign is that sometimes you spend a whole session just watching the player characters figure out what they want to do with their lives. Because I've run a lot of adventures in Khanbaliq-- and for a number of adventuring groups involving a variety of NPCs and developed locations, I think I did a good job of approximating spontaneity. Here are a few of things that happened that led to Beatriss and Tetsukichi's decision to leave Khanbaliq:
-- Phi Phong pushed things to far with her father-in-law Ansa. Not only was he not going to just "give" his adopted a son a title he had not earned, but we was thinking about throwing him and his nephew Tetsukichi out of the house so they could go out and make something of themselves.
-- Afu still believed that Gwinch had a large part in the slaving operations and was in the southwest border region raiding villages.
-- Imperial guards showed up one morning to question Anca. Beatriss the dutiful quasi-niece went along and was also questioned about her history in Khanbaliq. When asked about her fiance, Beatriss answered that she didn't know him well and that because he didn't seem serious in his intentions, she considered the engagement ended.
-- During another night out in Fun Town, Phi Phong sucessfully "re-directed" the unwanted amourous advances of a street thug onto a stray ("don't you think she's more your type?"). Somehow, this made Beatriss feel better about Phi Phong.
-- Members of the Zipangese diplomatic community-- just clerks it seemed-- were being arrested.
-- The new abbot of the Monastery of the Two-Fold Path made a surprise visit, seeling help with their ant problem.
-- Tetsukichi was summoned to the Imperial City . . .
. . . in the course of interrogation, Tetsukichi mentioned that he was thinking about leaving Khanbaliq to visit relatives in the Southwest border region. "Oh, really? We may have a job for you . . . "
The Emperor, it seemed, was also concerned about Gwinch. Slavery wasn't mentioned. Instead the Emperor's concern was that like first Governor Kawabi and then General Goyat, Gwinch too, had been turned from his commission since arriving in the Southwest border region. And now it was Tetsukichi's turn to go down there and find out what was going on and to punish any and all traitors.
Anca was also ready to leave Khanbaliq and the next several days were preparing a caravan that include Anca, his family, his warriors and their families and their many herds, plus a small group of monks from the Emperor's court, and finally the PCs and their family members, henchmen, and servants. Buyuk sent Beatriss a letter, apologize, and asking her to reconsider leaving. She tried to see him in the Imperial City, but finding that he was unavailable, left a terse message of farewell. And so the caravan left Khanbaliq, in a cloud of dust.