Place five RCX's on the table along with a number of obstacles. All RCX's must get the light intensity information back from Com Central (the computer). You must do this while maintaining line-of-sight. That is, when one RCX moves behind an obstacle, it must relay its message to Com Central through the other RCX's. If it is not in sight of any other RCX it must retrace its steps so that it is.