  A timely and long-term programme of kaon decay measurements at an
unprecedented level of precision is presented, leveraging the capabilities of
the CERN Super Proton Synchrotron (SPS). The proposed HIKE programme is firmly
anchored on the experience built up studying kaon decays at the SPS over the
past four decades, and includes rare processes, CP violation, dark sectors,
symmetry tests and other tests of the Standard Model. The programme is based on
a staged approach involving experiments with charged and neutral kaon beams, as
well as operation in beam-dump mode. The various phases will rely on a common
infrastructure and set of detectors.
