  The equator of star K2-290A was recently found to be inclined by 124+/-6
degrees relative to the orbits of both its known transiting planets. The
presence of a companion star B at ~100 au suggested that the birth
protoplanetary disk could have tilted, thus providing an explanation for the
peculiar retrograde state of this multi-planet system. In this work, we show
that a primordial misalignment is not required and that the observed retrograde
state is a natural consequence of the chaotic stellar obliquity evolution
driven by a wider-orbit companion C at ~2000 au long after the disk disperses.
The star C drives eccentricity and/or inclination oscillations on the inner
binary orbit, leading to widespread chaos from the periodic resonance passages
between the stellar spin and planetary secular modes. Based on a population
synthesis study, we find that the observed stellar obliquity is reached in
~40-70% of the systems, making this mechanism a robust outcome of the secular
dynamics,regardless of the spin-down history of the central star. This work
highlights the unusual role that very distant companions can have on the orbits
of close-in planets and the host star's spin evolution, connecting four orders
of magnitude in distance scale over billions of orbits. We finally comment on
the application to other exoplanet systems, including multi-planet systems in
wide binaries.
