Solving the heptic in two dimensions: Geometry and dynamics under   Klein's group of order 168
  There is a family of seventh-degree polynomials $H$ whose members possess the symmetries of a simple group of order 168. This group has an elegant action on the complex projective plane. Developing some of the action's rich algebraic and geometric properties rewards us with a special map that also realizes the 168-fold symmetry. The map's dynamics provides the main tool in an algorithm that solves "heptic" equations in $H$. 
Scott Crass