What does the threat of a "pointy reckoning" reveal about Abigail's true nature?

Abigail is not exactly the most moral person in Salem
village, as she has already engaged in an adulterous affair with John Proctor and now
she is involved in the fraud that was the Salem Witch Trials.  In Arthur Miller's play,
once the accusations have started flying and the trials are in motion, things become
much more serious and we see a side of Williams not revealed before.  If word gets out
that the story of witchcraft was a lie, she could lose her life, and in her desperation
to protect herself, she makes a direct threat against Mary Warren, who is nervous and
feels guilty for her part in the charade.  The "pointy" being a knife, and the
"reckoning" being a stabbing.  It reveals the lengths she will go to, and her potential
for violence if necessary.