VG - VG+ / VG.  1939 Harpers, stated first edition.  Hardcover with dust jacket.  You may not think of this as a rare title due to a fair number of reprint copies floating around which use the same cover design.  However, true first editions are not that common.  White was active as a published writer from 1927 until her death in 1944.  ‘Step In The Dark’ came out in 1939, which might be looked upon as towards the tail-end of her career - though she wrote and published five novels after this one.  Her best known works were published in the mid-1930’s (‘Some Must Watch’ and ‘The Wheel Spins’).