I have recently had an experience with this, due to a rather unfortunate timing on contrating the flu. I missed the first few days of the 2 classes I teach. The students had substitute instructors during these days, but had a different instructor each day i was out. This sometimes is a very unfortunate dilema due to trying to arrange coverage especially during flu season when so many students and instructors get sick. The students tend to become disengaged right from the start and it is very difficult to pull the class back from this when you happen to be coming back to class several days into it. you have missed the opportunity to make that first day impression and many times are facing a "hostile" class. I have been working very diligently on trying to redirect the class to get them re-invested in it. However; some of them became disengaged right at the start, this presents a rather distressing concern when u are running an accelerated course that is only 3 to 4 weeks long. What are some ways to try to re-direct an already disengaged class?