Smyrna, recalling this passage, does write that Thetis once released Zeus from chains; but there is no other reference to this rebellion among the Olympians, and some readers, such as M. M. Willcock, have understood the episode as an ad hoc invention of Homer's to support Achilles' request that his mother intervene with Zeus. Laura Slatkin explores the apparent contradiction, in that the immediate presentation of Thetis in the Iliad is as a helpless minor goddess overcome by grief and lamenting to her Nereid sisters, and links the goddess's present and past through her grief. She draws comparisons with Eos' role in another work of the epic Cycle concerning Troy, the lost Aethiopis, which presents a strikingly similar relationship – that of the divine Dawn, Eos, with her slain son Memnon; she supplements the parallels with images from the repertory of archaic vase-painters, where Eos and Thetis flank the symmetrically opposed heroes, Achilles and Memnon, with a theme that may have been derived from traditional epic songs. Thetis does not need to appeal to Zeus for immortality for her son, but snatches him away to the White Island Leuke in the Black Sea, an alternate Elysium where he has transcended death, and where an Achilles cult lingered into historic times. Mythology Thetis and the other deities Pseudo-Apollodorus' Bibliotheke asserts that Thetis was courted by both Zeus and Poseidon, but she was married off to the mortal Peleus because of their fears about the prophecy by Themis (or Prometheus, or Calchas, according to others) that her son would become greater than his father. Thus, she is revealed as a figure of cosmic capacity, quite capable of unsettling the divine order. (Slatkin 1986:12) When Hephaestus was thrown from Olympus, whether cast out by Hera for his lameness or evicted by Zeus for taking Hera's side, the Oceanid Eurynome and the Nereid Thetis caught him and cared for him on the volcanic isle of Lemnos, while he labored for them as a smith, "working there in the hollow of the cave, and the stream of Okeanos around us went on forever with its foam and its murmur" (Iliad 18.369). Thetis is not successful in her role protecting and nurturing a hero (the theme of kourotrophos), but her role in succoring deities is emphatically repeated by Homer, in three Iliad episodes: as well as her rescue of Zeus (1.396ff) and Hephaestus (18.369), Diomedes recalls