Iocane (object)

Iocane is a fictional poison from the movie The Princess Bride. From The Princess Bride Wiki, "Iocane powder is noted as being one of the deadliest poisons known to man.  It has no odor, no taste, and will dissolve instantly when poured into liquid. However, one can build up an immunity to iocane by gradually ingesting trace doses over time."

When discussing iocane in RICIN, Dr. McClellen makes several references to The Princess Bride.

It is revealed at the end of RICIN that Inspector Davis has successfully built up an immunity to iocane.