Most of the fifth (and final) book is a discussion of paranatellonta via the myth of Andromeda and Perseus.Manilius, Astronomica, 5.538618. Manilius recalls how Andromeda was chosen to be sacrificed to a sea monster by her parents; Cepheus and Cassiopeia. Andromeda was chained to a cliff but before the creature could consume her, Perseus (who had just vanquished Medusa) arrived. He instantly fell in love with Andromeda, killed the sea monster, and saved the young woman's life. According to Green, the digression, which is by far the longest in the poem, "is very well chosen, in as much as no other mythological episode involves so many future constellations interacting at the same time; Andromeda (e.g.5.544), Perseus (e.g.5.67), the Sea Monster – strictly, Cetus (cf.5.600), but often referred to in more generic terms during this story as belua (5.544, 608) and monstrum (5.581)Medusa's head (e.g.5.567), and Andromeda's parents, Cepheus and Cassiopeia". Green says the story is perfect for Manilius; he is able to use it to justify the constellations' proximity to one another and their eternal arrangement, as he had previously argued in 1.354360.Green (2014), p. 46. Conversely, Housman compared it unfavorably to Ovid's version of the story and called Manilius's retelling "a sewn-on patch of far from the best purple" (purpurae non sane splendidissimae adsutus pannus).Manilius & Housman (1930), p. 70. A similar sentiment was expressed by the Cambridge classicist Arthur Woollgar Verrall, who wrote that while the episode was meant to be a "show piece", it comes across as "a poor mixture of childish rhetoric and utter commonplace".Verrall (1913), p. 630. Between lines 5.709–10, there is a large lacuna, meaning that at least some of the work is missing, and then the last few lines of the book concern stars and other stellar phenomena. The book ends with a simile about the "res publica of stars".Volk (2009), pp. 10910.Volk (2009), p. 270. This section – in which Manilius proposes that the stars constitute an elaborate and organized system, defined by a hierarchy that prevents "cosmic disaster" – seems to Volk to be a way for Manilius to assert the legitimacy of the Roman state through analogy.Volk (2009), p. 110.
