Assertions of John the Baptist's identity as the returned Elijah are commonplace in New Testament scholarship. Attention has then tended to focus on whether the returned Elijah was regarded as the forerunner of the Messiah or of God himself. Surprisingly, the logically prior question of how someone could be regarded as Elijah returned has received scant investigation. This article explores what it might mean to describe John the Baptist as the returned Elijah, suggesting that we need clearly to distinguish this concept from Elijah typology. If, as is argued here, the expectation of Elijah's return in Mark's Gospel points to John the Baptist's angelic identity, this has interesting ramifications for other NT issues such as Christology and eschatology.