She knows she has to tell Mal sometime, she can't keep it a secret forever, and she decides, after this run to Jiangyin (a place Simon and River aren't too keen on going back to), she'll tell him. She'll tell everyone. Zoe finds herself sticking close to Inara, who decided not to leave after all, and it's good, Zoe figures, because she's going to need someone like her to show her what to do. Not that she thinks companions are versed in child rearing, but she still probably knows more than all of them.
They get to Jiangyin, a different side than where the hill folk lived, and do their business. Invited to stay to enjoy food and beverage, none of them can say no to that. Especially not Zoe. It puts off having to tell Mal about being pregnant. As they're sitting around the table, she's mostly zoned out until the magistrate starts talking about the man they have in their care. The whole moon still doesn't have a reliable doctor, especially not for someone hurt as the man they have. A wound to his chest, deep and through, but still somehow alive. The description chills Zoe, makes her stand up as Simon agrees to take a look.
Simon's back in less than ten minutes, giving a sidelong glance to Zoe even as he talks to Mal, and the two of them disappear. Mal comes back but Zoe's tuned out, standing with her arms crossed, looking out of a window.