TheCodeBreakers
by leaving doubled letters unenciphered, as the s's in Gross and crossing:
XELWA OHWUW YZMWI
HOMNE OBTFW MSSP1 AJLUO EAONG OOFCM FEXTT CWCFZ
YIPTF EOBHM WEMOC SAWCZ SNYNW MGXEL HEZCU FNZYL NSBTB
DANFK OPEWM SSHBK GCWFV EK.MUE. A message of
this length would alone suffice for the solution of a Play-fair, and
there were four others in the same key, including one of 335 letters,
beginning XYAWO GAOOA GPEMO HPQCW
JPNLG RPIXL TXLOA NNYCS YXBOY MNBIN YOBTY QYNAI . . .,
for Lieut Kennedy considers it advisable that he pilot PT boat tonight X .
...
These five messages detailed the rescue arrangements, which offered
the Japanese a chance to get not only the shipwrecked crew but the force
coming out to save it. All of them could have been solved within an hour
by even a moderately experienced cryptanalyst. Yet at 10 p.m. the
operation went off without the least hint of enemy interference. It seems
annaabi.ee 
