Distance covered: 34,227 km (21,268 miles)
Subjects found: 75
Saturday's meeting was brief, and bittersweet for M.
It was her first contact in three years with a world she thought had forgotten her, a world she still remembers but can no longer reach.
Only later did we learn that M's ever-jealous "husband" had been watching and waiting impatiently nearby. She called me the same evening in tears, having been severely berated by her father-in-law for taking her child out of the house.
M's role here in China is essentially that of a baby-making machine. Every day, she says, her parents-in-law demand a second baby; this time, they want a boy. M doesn't want any more Chinese babies, but is given no say in the matter.
For the next two days Moreno and I waited, frustrated in our attempts to organise a second meeting. Never in my life have I spent so much time and money on phone calls as I have here in the past twelve days.
"Luck and persistence" is the motto Moreno and I have adopted over the past nine months. It has served us well, and seen us through our most challenging times. On the third day after our meeting, with our chances seeming ever slimmer, we were given a second opportunity to see M.
This time, we were able to spend a full ninety minutes together - without her child. We sat and talked about everything and nothing - a small pleasure that has been denied M these past three years, and a very welcome change from the interminable days spent at home alone with her baby.
I explained to M how we're able to help her, and how we want to use her story to help others in danger. We watched parts of her wedding DVD together, and even met her "husband".
Will M remain here in China as a baby-making machine, or will she claim back her own life in Vietnam? The question is not as simple as it may seem. Much remains to be discussed, and many challenges still lie ahead.
For now, Moreno and I have a long journey before us. We're heading towards Tibetan China and using what little time remains to search for our nine final portrait subjects on this side of the Himalaya.
M has been greatly encouraged in these past few days by audio messages sent in by friends and strangers from around the world, and I thank those of you who took the time.
Yesterday, M's story was promoted by Walk Free, a global anti-slavery movement with over 4.7 million Facebook followers, and our website has been buzzing ever since. We'll be seeking more exposure over the coming weeks; the more people that see the horrors of human trafficking, the closer we come to ending it.
All we need is a little luck and persistence.
To follow M's story and our own, sign up here.