In a changing knowledge society, many workplaces experience a great number of reforms, implying improvement, new ways of working and professional learning. When a reform is introduced, however, does a professional act as an ever-moving machine--a "perpetuum mobile"--always learning with full energy? In this article, I ask the following: What characterises the learning dynamics of pastor networks as they go through a reform? I will follow how a reform is enacted in three different situations amongst pastors in the Church of Norway as a national reform of the church services is carried out. Through a thematic content analysis of an ethnographic fieldwork study of three congregations in Norway, professional learning is analysed as the dynamics between substance, force and time. I argue that introducing something new like a reform does not always effectuate high-powered learning. When professionals experience a reform, socio-material elements energise or slow each other down and generate various professional learning dynamics. The findings pinpoint how professional networks are in constant change, and thus enact new reforms differently. This study can contribute to exploring and nuancing professional learning dynamics, as well as raising questions about reforms as resources for professional learning.