2004 Mazda RX8 turns over but won't start

I have a 2004 RX8. Purchased used about a year ago. The car has been sitting for about a month.
Went to start it and the battery was dead. Put a charger on it overnight. Went to start it this morning and it turns over but won't fire. No smell of fuel around the engine. Tried a little starting fluid but that didn't help either. Let the car sit and still nothing. Just new plugs installed by a local garage back in June. Any suggestions? The car isn't driven that often, bought it with 125,000 miles and it has 128,000 miles a little less than a year later.