Paradise Lost

Paradise Lost is a special skill book given to the player in Underworld by Tulip. It increases the Speech skill by 1. Like standard skill books, its effect is doubled with the Comprehension perk. Tulip in Underworld will give you a spare copy for free since they "have enough copies laying around", if you talk enough with her,

If dropped, this item appears as a copy of Lying, Congressional Style.

Other information

 * Paradise Lost is a real-life 17th century English epic poem by John Milton. As it is a piece of fine literature, the speech increase is expected.
 * A mistake was made by the game's writers: Tulip explains that Underworld is based on this book which she says is about a man making a trip through the underworld. The book she refers to and the one Underworld is based on (including references such as the ninth circle etc.) is actually Dante's Inferno, part of his Divine Comedy. Milton's Paradise Lost is an epic poem explaining the fall of Satan (and religions from his viewpoint) and the human exile from Eden, in which the underworld is only briefly discussed as the new home to the fallen angels.
 * It's possible this "mistake" was intentional, due to the title Paradise Lost being a mild pun on the destruction of the idyllic United States following the Great War.