One Piece, Vol. 15

Nami's sick! Now the Merry Go is without her navigator! Luffy and crew have but one choice—find land and hopefully a doctor. They miraculously stumble upon Drum Island, where it is eternally winter, but upon arriving they find out the island has only one medical professional—and she's a witch! With Nami's life on the line, Luffy sets out through the snow-laden fields to find this doctor, witch or not!

Volume 15 of the One Piece manga series by Eiichiro Oda.