It was a pretty good plan...
I had an 8AM conference call so I got up at 6, cup o' joe, and fired up the egg. Wanted to preheat to 350 then back down to 250 (I don't often preheat... I was just trying it out. I was also kinda experimenting and splitting the difference between an Elder Ward brisket at 275 and other recipes at 225.) As (bad) luck would have it, it took too long to get up to temp and back down, so, I got it to about 350, threw the brisket on, shut down the vents, and went on my call.
Normally, when I put the meat on and shut down the vents, the temp drops quickly, so I figured a few minutes at 350 before dropping wouldn't hurt. Yesterday, I came back after my call and to my horror, the egg temp had hardly dropped. The internal temp was crawling toward 140. Panic!! I kept the egg shuttered and it finally dropped down to 240. I let it go to 225. The internal temp soon got to 171 and hovered (thankfully) for at least a couple of hours. I went on another call. Came back and the egg had now dropped to 190 as the internal hit 178! I was going nuts. I opened the lid and the fire had gone out!! Big ole hole in the middle. That has never happened before (This working thing with conference calls has GOT to go!). So I pulled the brisket out, took out the drip tray, stone and grid, and relit the fire. Pulled out a few take-out menus figuring the brisket was DOA.
I put it all back together and managed to get the temp back to about 240. The meat hit 170 again and hovered for another hour before climbing to about 196 when I pulled it. Wrapped it in foil, stuck it in a cooler and said a prayer.
Unwrapped that sucker at 6PM (it was about a 5 pounder and it cooked for about 7-8 hrs). It was FABULOUS! Nice and crusty on the outside, moist and juicy inside, with a little smoke ring around the edge. Now it mighta been even better had I not screwed it up to a fare-thee-well, but I was amazed. Maybe I'm crazy, but I figure it had to have been the forgiveness of the egg. I can't imagine screwing up a recipe like that on any other kind of grill/smoker/oven and be able to enjoy what came off it.