Flops on holomorphic symplectic fourfolds and determinantal cubic   hypersurfaces
  We study the birational geometry of irreducible holomorphic symplectic varieties arising as varieties of lines of general cubic fourfolds containing a cubic scroll. We compute the ample and moving cones, and exhibit a birational automorphism of infinite order explaining the chamber decomposition of the moving cone. 
Brendan Hassett and Yuri Tschinkel