Joe Hill's novel NOS4A2 contains references to not only other works of his, but some of his father Stephen King's works as well. At one point in the book, a minor character named Sigmund de Zoet listens to Frobisher's Cloud Atlas sextet. Robert Frobisher and his eponymous sextet are from David Mitchell's novel Cloud Atlas. Presumably Sigmund is a descendant of the title character of another novel by Mitchell, The Thousand Autumns of Jacob de Zoet, which is set in 1799-1817. All of Mitchell's books are connected. Cloud Atlas features the same soul being reincarnated in several people over centuries, with each incarnation bearing a comet-shaped birthmark. Two of these individuals, Luisa Rey and Timothy Cavendish, appeared as minor characters in Mitchell's first novel, Ghostwritten. Another character in Ghostwritten, Katy Forbes, has a comet-shaped birthmark. Since Rey, Cavendish, and Forbes were all alive in the 1990s (when Ghostwritten takes place), the soul must have been divided among them somehow. Two sections of Cloud Atlas are set in future time periods that are incompatible with the CU's established future, and therefore likely take place in an alternate universe. One of these sections, "An Orison of Somni~451," has a reference to the title character having read Ireneo Funes' Remembrances, a reference to Jorge Luis Borges' short story "Funes the Memorious." Also, Somni refers to a fabricant living doll of Zizzi Hikaru, a Japanese virtual sex symbol from another novel by Mitchell, number9dream, which is set in the present day.