It has been known for some time that holomorphic symplectic varieties can be constructed from moduli of curves or sheaves on a four-dimensional hypersurface Y of degree 3 in projective space. By seminal work of Kuznetsov, this can be understood in terms of certain subcategories in the derived category of Y that behave like the derived category of a K3 surface. In the talk, I will try to give concrete geometric interpretations of these facts and, if time allows, report on more recent results of joint work with Nagai Y. and D. van Straten.