Hitherto the Greeks have had a decided advantage in battle with the Trojans, and nothing has been done to carry out the promise which Zeus made to Thetis. But now the father of gods and men begins to take decisive measures to fulfil his pledge; the gods are forbidden to interfere between the rival armies, and in the next day's battle the Greeks are driven back in panic to their camp, while the Trojans, contrary to their custom, keep the field all night, intending to attack the Greek stronghold in full force next day. So despondent are the Greeks that an embassy is sent with an offer of magnificent gifts to Achilles, if he will lay aside his anger and come to the help of his distressed countrymen. Achilles refuses all compromise, and the rest of the night is occupied by the bold raid undertaken by Diomede and Odysseus on the Thracian camp. At the opening of the eleventh book our attention is concentrated on the valorous exploits of Agamemnon, who is at length compelled to retire by a severe wound in the arm; Diomede is pierced through the foot by an arrow from the bow of Paris, and Odysseus, Machaon, and Eurypylus are also disabled. Patroclus is sent by Achilles to inquire of Nestor concerning the fortunes of the Greeks, and Nestor then makes the suggestion which marks the turning-point in the first act of the great epic drama: if, he says, Achilles will not go to the field himself, at least let him send Patroclus to lead the Myrmidons[1] against the Trojans. Nothing comes of the proposal for the present, but it is to bear fatal fruit both for Patroclus and Achilles in the near future. The Greeks are again driven behind their defences, and a furious struggle ensues, at the end of which the gates of the camp are demolished, and the Trojans, led by Hector, are on the point of setting fire to the ships. [1] The followers of Achilles At this moment the attention of Zeus is withdrawn from the battle, and Poseidon seizes the opportunity to interfere in favour of the Greeks. By his influence the scale is turned again, Hector receives fearful injuries from a huge stone hurled by Ajax, and the Trojans are driven headlong across the plain. Zeus is lulled to sleep by the contrivance of Hera, and when he awakens it is to find his whole scheme of vengeance on the point of being frustrated. In great anger he sends a peremptory message to Poseidon to withdraw from the battle, and lays his commands on Apollo, who brings back Hector, healed and whole, to the field, and leads the Trojans once more to the assault of the camp. In spite of the desperate valour of Ajax, the Greeks are driven back to their ships, and the Trojans bring torches, with the intention of burning the whole fleet.