Ok here's how I see this story but feel free to change and mould as you please if you wanna add something in a different direction:
Think of a modern day version of the Count of Monte Cristo e.g. a guy or girl (whatever people decide) ends up locked up for a crime he/she didn't do. His/her closest friend(s) betrayed him/her and set them up so they could get together with his/her partner. Somehow the main character is out now, maybe having served his/her time, got parole, sucessfully appealed
As I walked through the clearing I took a deep breath of the cold mornings air and allowed it to invigorate me.
I hadn't slept a wink in twenty four hours and barely grasped more than a few hours each night in the last week. I ought to be feeling exhusted but I was full of energy, rejuvenated- freedom did that to you.
I needed to find shelter. Although I wasn't sleepy at the moment I knew I would start to flag soon and a meal wouldn't be a bad idea either.
Once I was settled I would be able to turn my thoughts to planning.
Not that I hadn't started that. Five and a half years was ample time to brood over what my moves would be when I was out. So I had ideas, I knew just how my vengeance would be extracted... but I needed supplies and to coerce support from other people to make this work.
There was no way I was going to rush this and spoil everything. There could only be one attempt at doing this sucessfully. If I lost the element of surprise I would lose everything.
Even my freedom would be meaningless if I couldn't have my revenge.