This work evaluates an educational proposal, based on the Flipped Classroom principles, implemented in online learning during the lockdown caused by Covid-19 pandemic. The proposal was implemented in a Portuguese secondary school class and combines asynchronous classes (ASC) with synchronous classes (SC). We collected data using quantitative and qualitative methods, to characterise the learning environment, and its influence on the students’ engagement. The integrated analysis of the data reveals that the proposal created an adequate learning environment, organised, and supported by a robust social presence of the teacher. The design of the ASC enhanced student-content interactions leading to high rates of commitment to the tasks, which ensured an efficient preparation of the ASC. The SC division into learning episodes allowed us to understand the influence of episode design on the interaction patterns developed. The dynamic and interactive approaches of SC allowed the development of subject contents initiated in ASC. Despite the design of some episodes it has allowed measurable improvements in the number of student-student interactions it has also conditioned the collaborative construction of knowledge based on research processes.