In the weathered lobby of a hilltop hotel in Gongshan, Nujiang, the local priest offers me a cigarette. It seems customary, in the border valley towns of Yunnan province in southwestern China, for men to offer cigarettes before starting a conversation. Evening Mass has just ended at the local church, and Father Ruo Wang gave me a ride up here.

I’d rushed down from Dimaluo, a village higher north in the Nujiang valley, at the last minute. After hearing that I was looking for someone from the church, his mother had given me his number. When I called, Ruo Wang told me that he was going to be leading Mass in Gongshan in an hour, and that I could photograph it if I liked.

With that single phone call, the doors to the valley’s Catholic villages opened to me. Before that, I’d been in Nujiang for a week and hadn’t quite been able to get access. The famed Zhongding Catholic Church in Bingzhongluo that I’d travelled all the way to see was closed for renovation. There had been a priest on site, diverting visitors away. He said he’d received instructions to speed up the works, which were for a separate building beside the church to accommodate growing tourism. He seemed stressed out and hesitant to answer questions. In a later WeChat voice memo, he told me that the Chinese government had been doubling down on efforts to quell religious activity.

• Tags: China, Issue 44, Zachary Tang