Booklist believed the book would appeal to followers of Brian Jacques' Redwall series. Into the Wild was critically well received. Themes include family, loyalty, death, courage, and survival. The style has been compared to the Harry Potter series, J.R.R.

The story uses a lexicon with words such as 'Twoleg' substituted for 'human' or 'new-leaf' for 'spring'. She feels that Erin Hunter must have a consistent voice the entire series. Holmes has compared the style of the book to a different language as the books are written by three separate authors. After creating one storyline Holmes brought in Kate Cary to finish writing the book as Holmes went behind the scenes to edit and supervise the details. The series began in 2003 when HarperCollins requested Holmes to write a book on feral cats. The novel is written from the perspective of Fireheart (previously known as Rusty for a short time, then, for most of the book, Firepaw). 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. The story is about a young domestic cat named Rusty who leaves his human owners to join a group of forest-dwelling feral cats called ThunderClan, adopting a new name: Firepaw. The book has been published in paperback and e-book formats in twenty different languages. It is the first novel in the Warriors series.

The novel was published by HarperCollins in Canada and the United States in January 2003, and in the United Kingdom in February 2003. Into the Wild is a fantasy novel about the lives of fictional cats, written by a team of authors using the pseudonym Erin Hunter.

Into the wild book erin hunter