  We in the physics community expect the LHC to uncover new physics in the next
few years. The character and energy scale of the new physics remain unclear,
but it is likely that data from the LHC will need to be complemented by
information from a lepton collider which can provide for precise examination of
new phenomena. We describe the concept, accelerator design, and detector R&D
for a high energy Muon Collider as well as the challenges associated with the
machine and its detector environment.
