Twice in 2yrs. I have turned the key with good batery and starter yet no start

What is your question?

The first time this happend, I tried 40 or so times with no success. towed it to a mechanic and when he went to work on it the next morning it started right up. He tried it 20 times and it kept starting. He checked and cleaned connections to the starter. No problems for 2months and it happened again(this afternoon and will try it tomorrow) yet all the same symptoms. The key turns freely in the ignition. Since the first incidence the glow plug light goes on after the car starts.(not during normal starting process)