General Discussion

After departing DFW a man in a white shirt and dress slacks came from coach and spoke with the flight attendant for a good few minutes and then went into the cockpit. Shortly thereafter, the pilot informed us we were landing but there was nothing mechanically wrong with the plane. Guessing the unknown male was an air Marshall but it was all so very nerving. Asked the flight attendant if she had seen anything like this and she replied, "not in 26 years". I was impress as to how rapidly planes were grounded.