"They would see no farther, and attempt to guard no farther. After
they had provided a plan for the killing, and a means by which the
killer could cover his trail and escape from the theater of the
homicide, they would believe all the requirements of the problems
met, and would stop. The greatest, the very giants among them,
have stopped here and have been in great error.

"In every crime, especially in the great ones, there exists a third
element, preeminently vital. This third element the master
plotters have either overlooked or else have not had the genius to
construct. They plan with rare cunning to baffle the victim. They
plan with vast wisdom, almost genius, to baffle the trailer. But
they fail utterly to provide any plan for baffling the punisher.
Ergo, their plots are fatally defective and often result in ruin.
Hence the vital necessity for providing the third element--the
escape ipso jure."

Mason arose, walked around the table, and put his hand firmly on
Samuel Walcott's shoulder. "This must be done to-morrow night," he
continued; "you must arrange your business matters to-morrow and
announce that you are going on a yacht cruise, by order of your
physician, and may not return for some weeks. You must prepare
your yacht for a voyage, instruct your men to touch at a certain
point on Staten Island, and wait until six o'clock day after
tomorrow morning. If you do not come aboard by that time, they are
to go to one of the South American ports and remain until further
orders. By this means your absence for an indefinite period will
be explained. You will go to Nina San Croix in the disguise which
you have always used, and from her to the yacht, and by this means
step out of your real status and back into it without leaving