However, the reintegration poses challenges. The returned suffer from effects similar to those that may be seen after severe concussion, such as disorientation, sleep disturbance, and wandering. Former professionals among the returned are moved to menial jobs when it becomes clear that, although they can perform rote tasks, they can no longer engage in spontaneous problem solving or planning, and that even their apparent consciousness may be an illusion. This behaviour adds to the growing sentiment that the returned are different from their former selves. However, while the returned generally function sluggishly during the day, a doctor named Gardet (Frédéric Pierrot) has become suspicious of the returned after observing some of them clandestinely attending animated meetings, conducted in the middle of the night, during which their symptoms seem to disappear.