"Rudy Nappi"@en . . . "Hardcover"@en . "175"^^ . . "The Masked Monkey"@en . "ISBN 0-448-08950-5"@en . . . . . "__WIKIA_BANNER__ Danger on Vampire Trail is the 50th book in The Hardy Boys series. It was first published in 1971 by Grosset & Dunlap."@en . "1971"^^ . . "Danger on Vampire Trail"@en . "__WIKIA_BANNER__ Danger on Vampire Trail is the 50th book in The Hardy Boys series. It was first published in 1971 by Grosset & Dunlap."@en . "The Bombay Boomerang"@en . "The Hardy Boys"@en . . "Danger on Vampire Trail"@en . . . . . .