Should I Tell My Boss Our Brand New Hire Is Already Plotting To Overthrow Him?

GOOD QUESTIONI work in HR, and we had a new recruiter start yesterday. She seems to struggle with issues from her previous job with "corporate bullying" and may be unstable (lots of home problems, arrived extremely late on first day, complained about previous position extensively, etc.).

Today (her second day of employment), she pulled me aside and spoke disdainfully of my supervisor, who heads the HR department, saying that I could have his job in two years and everyone in Recruiting hates him, in an attempt to try to "recruit" me to sabotage my boss. This is all too much drama for someone starting their second day, and this tells me that her fellow recruiters are badmouthing my boss and telling her how awful he is. I'm not sure if they are encouraging her loose cannon behavior or are working as a group on this plot. But hatching a plan to overthrow my boss is taking it too far, makes me very uncomfortable, and is a crazy distraction. How should I approach this bizarre situation? Should I warn my boss?