Into the Wild is a fantasy novel written by Kate Cary under the pseudonym Erin Hunter after concepts and outlines created and developed by Victoria Holmes. The novel was published by HarperCollins in Canada and the United States in January 2003, and in the United Kingdom in February 2003. It is the first novel in the Warriors series. The book has been published in paperback, e-book, and Amazon Kindle formats, and in twenty languages. The story is about a young domestic cat who leaves his human owners to join a group of forest-dwelling feral cats called ThunderClan. He is trained to defend and hunt for the Clan, becomes embroiled in a murder and betrayal within the Clan, and, at the end of the book, receives his warrior name, Fireheart, after a battle with another Clan.