Challenge Blue Mask! - Anthony Morton (John Creasey) 1939 - J. B. Lippincott Company, Philadelphia - First American Edition A fine copy in fine and thus scarce dust jacket.

Featuring the legendary ‘Baron’, debonair jewel thief turned detective.
  First published by Sampson Low, London the same year under the title ‘The Baron at Large’.

References: Reilly, ’
Twentieth-Century Crime and Mystery Writers’ (1980), 382. James, ‘Great British Fictional Detectives’, 50.

Octavo (book size 19.5x13.7cm), pp. [2] 315 [3]. In publisher’s blue cloth, spine lettered in red, with Lippincott Mystery logo to spine and front panel in red, top edge tinted red, front edge untrimmed, lower edge trimmed. Dust jacket priced ‘US$2.00’ to lower corner of front flap.
  Condition: Some offsetting to endpapers else fine in fine dust jacket   Ref: 110338   Price: HK$ 3,500