off the rails

prepositional phrase4

1. •
   In an abnormal manner, especially in a manner that causes damage or malfunctioning.
2. •
   Off the intended path.

   • ... but the plan came off the rails when infuriated Communists called it "ideological provocation" and warned against "kindling political confrontation — 2009
3. •
   Out of control.

   • I reckon it's pretty astonishing that none of us did go off the rails. There really was no telling how any of us would deal with the pressures and the fame. — 2009
4. •
   Insane.