beneath the surface
Into or among the deeper aspects of something, as opposed to those that are most easily identified. When you write your book reports, please look beneath the surface of the text and analyze the author's stylistic choices.
below/beneath the ˈsurface
what you cannot see but can only guess at or feel: She seems very calm but beneath the surface I’m sure that she’s very upset.Beneath the surface of this beautiful city there is terrible poverty and suffering, which tourists never see.