Thanks to all who helped with their ideas on the big turkey cook. The 21 lb bird soaked in salt/sugar brine for about 48 hours before starting to cook on Saturday morning. It sat, breast up, on the grill with a 9" pie pan under the grill, and roasted at 225 initially, rising to 325 near the end. The results were fantastic. We had about 30 people at dinner and many expressed their amazement at how juicy the turkey was. I loved the smoke flavor! I filled the drip pan half full of water before starting the bird, It was half full of drippings when the cook was done. I suppose it served as a heat deflector, because the bird did not get scorched, even on the bottom.