  This paper continues the development of a simplicial theory of weak
omega-categories, by studying categories which are enriched in weak complicial
sets. These complicial Gray-categories generalise both the Kan complex enriched
categories of homotopy theory and the Gray-categories of weak 3-category
theory. We derive a simplicial nerve construction, which is closely related to
Cordier and Porter's homotopy coherent nerve, and show that this faithfully
represents complicial Gray-categories as weak complicial sets. The category of
weak complicial sets may itself be canonically enriched to a complicial
Gray-category whose homsets are higher generalisations of the bicategory of
homomorphisms, strong transformations and modifications. By applying our nerve
construction to this structure, we demonstrate that the totality of all (small)
weak complicial sets and their structural morphisms at higher dimensions form a
richly structured (large) weak complicial set.
