Branko Nikolic and I have attacked the 45 year old problem of characterising Cauchy completeness for differential graded categories, in the Lawvere sense for categories enriched in chain complexes. We begin by dealing first with G-categories, that is, categories enriched in integer graded abelian groups. This follows last week's talk by Branko so come equipped at least with the knowledge of the symmetric closed monoidal structure on chain complexes.