  The prospect of an ep collider involving an LHC proton beam and a new
electron accelerator is discussed. Configurations reaching centre of mass
energies a factor of 5 beyond HERA are possible with luminosities of the order
of 10^33 cm^-2 s^-1. The physics programme with such a facility is surveyed and
possible machine and detector lay-outs are sketched.

High Energy Physics - Experiment