Many-body quantum systems have come under intense focus in recent years, with a variety of experimental systems—atoms, ions and solid state qubits--emerging as key platforms for inquiry.  One key set of questions concerns the ability of any such delicately tailored quantum system to relax to equilibrium when it is isolated from the environment, and whether such dynamics might have universal features.  Research in our laboratory on magnetic quantum fluids comprised of Bose-Einstein condensed atoms (BECs) has a remarkable potential to address this problem.  A key experimental discovery of our group is the existence of a sharp phase boundary in antiferromagnetic sodium BECs through quantum quench dynamics.  In this talk I will show data demonstrating the rich interplay between many actors--magnetic interactions between spins, the influence of external magnetic fields, and the spatial quantum dynamics of many interacting modes that all compete to determine the non-equilibrium behavior.