Welcome, Bob! I agree with Ed that 13 hours is a long time for a 12 lb turkey! The last time I did a whole turkey, it was 12.6 lbs, smoked at 240° for 5:15 to hit 165° in the breast. I also stuff with equal amounts of chopped celery, carrots and onion (mire poix) to help stabilize the cook, and add some really nice flavor to the meat.
If the turkey is already injected with a solution (like so many are), I don't brine. I'll only brine a turkey or chicken that doesn't have solution added.