Through the Looking Glass is Carroll's sequel to Alice in Wonderland. A few of the characters who appeared in Wonderland reappear in Through the Looking Glass, including Alice's cat and the Hatter and the Hare. More significantly, however, is the way in which the sequel mirrors the first book: it begins inside on a snowy November 4, while Wonderland began outside on a sunny May 4; it employs the imagery of chess where Wonderland employs the imagery of playing cards; time and space vary dizzyingly in Through the Looking-Glass while size changes drastically in Wonderland. This is all even more significant when considering the main motif of the book, the looking-glass, or mirrors.
Even though both books are considered works of children's literature, and both reflect on the theme of growing-up, Through the Looking Glass approaches this theme in a more abrupt and less playful way. It is as if the troubles associated with approaching maturity are introduced in Alice in Wonderland and then met with resignation in Through the Looking Glass.