end of the great Siege of Deep Heaven against the Oyarsa of Earth. The siege starts to end (with the Oyéresu of other worlds descending to Earth) at the finale of the trilogy, That Hideous Strength. But there is still much to happen until the Oyéresu put an end to the rule of the Bent Eldil and, on the way, smash the Moon to fragments. In the Field of Arbol, the outer planets are older than the inner planets. Asteroids are called "dancers before the threshold of the Great Worlds." Eldila The eldila (singular eldil) are super-human spirits. The human characters in the trilogy encounter them on various planets, but the eldila themselves are native to interplanetary and interstellar space ("Deep Heaven"). They can, if they want, remain fixed to one point on a planet's surface - but that requires a conscious act on their part, without which they would instantly drift away into space. Certain very powerful eldila, the Oyéresu (singular Oyarsa), control the course of nature on each of the planets of the Solar System. They can manifest in corporeal forms. The title Oyarsa seems to indicate the function of leadership, regardless of the leader's species; when the Perelandran human Tor assumes rule of his world, he styles himself "Tor-Oyarsa-Perelendri" (presumably "Tor, Ruler of Perelandra"). The eldila are science-fictionalised depictions of angels, immortal and holy. (As Lewis implies in Chapter 22 of Out of the Silent Planet, the name Oyarsa was suggested by Oyarses, the name given in Bernard Silvestris's Cosmographia to the governors of the celestial spheres. Bernard's word was almost certainly a corruption—or a deliberate alteration—of Greek οὐσιάρχης [ousiarches, "lords of being"], used with the same meaning in the Hermetic Asclepius.) The eldila resident on Earth are "dark eldila"; in other words, fallen angels or demons. The Oyarsa of Earth, the "Bent One", is Satan. During the trilogy, Ransom meets the Oyéresu of both Mars and Venus, who are described as being masculine (but not actually male) and feminine (but not actually female), respectively. The Oyéresu of other worlds have characteristics like those of the corresponding classical gods; for instance, the Oyarsa of Jupiter gives a feeling of merriment (joviality). It is made clear that they are identical with the gods and goddesses of the Greco-Roman pantheon, but that the Greeks and Romans were wrong to worship them as gods—in fact, they are angels, faithful servants