Such matters as are appropriate for presentation must be presented in Acts, and each Act must contain only such events as can naturally, or by skilful management, be made to occupy the duration of a single day, [629] a requisite which is obeyed by Bhavabhūti in his Mahāvīracarita and by Rājaçekhara in his Bālarāmāyaṇa despite the difficulties presented by the effort thus to condense the epic. But it is essential that the events described shall not be disconnected; they must flow from the same cause, or issue naturally from one another. There should be an effective development of the plot within the Act; at the time when it comes to an end by the departure of the actors—three or four at most, one of whom should be the hero—at the moment when they seemed to have attained their immediate aims, a new motive should come into play, and a fresh impetus be given to the movement of the drama. But it is neither necessary nor usual that Act should follow Act without interval; on the contrary, anything up to a year may intervene between the action of one Act and that of the next; if the events as recorded in history covered more than that time, as in the case of Rāma’s fourteen years of banishment in the forest, the poet must reduce the period to a year or less. To reveal to the audience the events during such intervals the theory permits a choice of five forms of scenes of introduction (arthopakṣepaka), which serve also to narrate things, whose performance on the stage is forbidden by the etiquette of the drama. [630]