This paper describes some of the consequences of introducing a face-to-face contact during an online collaborative learning session. Previous research on the development of online groups has suggested a critical transition period at the midpoint of a collaborative task in which group members redefine their behavior. The purpose of the present study was to determine whether face-to-face contact between participants during this period influences the patterns of participation, interaction, affect and behavior over time. Results show that a face-to-face contact introduced at the midpoint of a collaborative task has a positive influence on participation. However, a time sequence analysis of interactions revealed a further transition which appears between the face-to-face contact and the deadline. This transition is characterized by a decline of participation and task-focused interactions. At the same time, the analyses revealed an increase of interactions oriented towards emotional regulation and coordination, as well as a greater need of face-to-face contact, desire to drop out, and use of synchronous communications. These findings are based on an in-depth and longitudinal examination of a small sample, which limits their generalizability, but they may have a number of implications for the design of blended learning programs and the facilitation of collaborative tasks in distributed learning environments.