Immortality in fiction Immortality is a popular subject in fiction, as it explores humanity's deep-seated fears and comprehension of its own mortality. Immortal beings and species abound in fiction, especially fantasy fiction, and the meaning of "immortal" tends to vary. Some fictional beings are completely immortal (or very nearly so) in that they are immune to death by injury, disease and age. Sometimes such powerful immortals can only be killed by each other, as is the case with the Q from the Star Trek series. Even if something can't be killed, a common plot device involves putting an immortal being into a slumber or limbo, as is done with Morgoth in J. R. R. Tolkien's The Silmarillion and the Dreaming God of Pathways Into Darkness. Storytellers often make it a point to give weaknesses to even the most indestructible of beings. For instance, Superman is supposed to be invulnerable, yet his enemies were able to exploit his now-infamous weakness: Kryptonite. (See also Achilles' heel.) Many fictional species are said to be immortal if they cannot die of old age, even though they can be killed through other means, such as injury. Modern fantasy elves often exhibit this form of immortality. Other creatures, such as vampires and the immortals in the film Highlander, can only die from beheading. The classic and stereotypical vampire is typically slain by one of several very specific means, including a silver bullet (or piercing with other silver weapons), a stake through the heart (perhaps made of consecrated wood), or by exposing them to sunlight. Mythical creatures Mythological beings are often used in modern fiction as characters, as a plot device, or even just as "window dressing". Such beings are often either immortal or associated with immortality. Tezuka Osamu's lifework Phoenix (known in Japan as Hi no Tori) had a phoenix whose blood would provide immortality. In various ages, many "heroes" and "heroines" would strive for immortality only to realize that there is something beyond eternal life. In one story titled "Rose Ham" (lit. "Next World Story") the last remaining human male who survived a holocaust, blessed (or cursed) with immortality through the phoenix blood, would create another beginning of life. In his immortal form, he would see a race of slugs, after gaining intelligence, destroy themselves in another holocaust. He would seed the earth with life that would become present day humans, and finally leave the earth to join his lover, who died billions of years ago, in heaven. In the Cthulhu Mythos created by H. P. Lovecraft, there is a race of "Fish-Men" known as Deep Ones. They stop aging after reaching adulthood and can breed with humans to birth offspring with this "eternal youth." This is a faustian bargain, as after reaching the age of 20, the Deep One Hybrids undergo a transformation from normal humans into Deep Ones. They also lose all concept of humanity and morality and go to live in the ocean with the Deep Ones and to worship the undersea deity Father Dagon, the Ruler of the Deep Ones and consort to Mother Hydra. Negative effects Since immortality is seen as a desire of humanity, themes involving immortality often explore the disadvantages as well as the advantages of such a trait. Sometimes immortality is used as a punishment, or a curse that might be intended to teach a lesson. It is not uncommon to find immortal characters yearning for death. In some parts of popular culture, immortality is not all that it is made out to be, possibly causing insanity and/or significant emotional pain. Much of the time, these things