The most implausible part of M. Night Shyamalan's THE HAPPENING:
When a lone sweater vest transformed Mark Wahlberg into a high school biology teacher.
What exactly was Night thinking casting him here? That it would instill fear in audiences because this was the guy who was supposed find a scientific explanation for the Happening? Marky-Mark as the earnest biology teacher made the whole "plants making people kill themselves" concept seem, at the very least, incredibly plausible.
Better luck next time, Night.