From gaseous perception, through the any-space-whatever and to the originary world, the universe coheres: but this mise-en-scene does not yet describe a determined situation. A determined situation has geo-historical coordinates – even if these coordinates are imaginary or semi-fictional (in the present, past or future). A determined situation is one which designates a social organisation and relates it to individual lives; is one with internal and external histories; is one mapped upon a landscape through architecture, infrastructure and lines of communication. This, for Deleuze, is realism. Accordingly, the first task of the action-image is to uncover and so determine the coordinates of the situation; and it will do so through the function of the character. This is action → situation. Here the character's actions reveal the situation of the film-world through an unfolding of events. And the way in which the situation is revealed engenders the sign series which composes the coordinates of the image. The first sign of composition describes an index of lack; the sequence responding to an ellipsis by fulfilling the quest to reveal the situation in which the characters find themselves. Every situation is amenable to a full explication, although it may retain complexities. Accordingly, the second sign of composition is an index of equivocity: two related and undecidable situational alternatives. Finally, the world may be discovered as a nexus of situations, a vector, where each determinate is aligned with a different character, class, gender, event, or condition, and so on, describing the line of a universe.

The action-image (action → situation), accordingly, is constituted by the sign series: index of lack (first sign of full molar composition) ↔ index of equivocity (secondary sign of composition) ↔ vector (sign of genetic forces).

Index of lack

The situation is not given in-and-for-itself; rather, it is revealed as a function of the actions of the character. This not-yet-given begins as an ellipsis which exists to be filled. In this way, the environment is that which must be explored, discovered and then described. Coordinates must be mapped and lines of constitution traced. This ellipsis is an index of lack through which ‘an action … discloses a situation … The situation is thus deduced from the action, by immediate inference, or by relatively complex reasoning’ (C1: 160).