Here is a much better review than anything I could come up with and will probably inform you on a much greater level. Actually check that...first what would help you out more would be this introduction video by Mark himself.
When we decide to pursue the Wild Goose we often what we often find out is that there are obstacles that we may have to overcome. Actually the imagery that Batterson uses is cages. After Batterson invites us to reimagine our faith pursuits he begins to help us define and guide us out of these many cages. Some of the cages that Mark leads us through are responsibility, routines, assumptions, guilt, failure and fear.
I don't know about you but I often times find myself in one or more of these cages.