When did it all go so wrong? (Up for adoption)

Part 12 (Mini)

Jack

I looked up at everyone in complete shock.
Mark was being abused and no one knew...
He tried to kill himself because he was being hurt and we all just left him, Alone, with his abuser.
How were we so blind...?
I stood up and walked into the living room to find Mark but he wasn't there. I started to panic but then I saw a sticky note on the counter.
'Went for a walk. I'll be back in 30.
-M'
I let out a breath I didn't even know I was holding.
I showed them the note and we went to sit down. I went and got some water.
We all say in Marks living room. Bob, Wade and I on the couch and Felix and Marzia where seated on the floor.
We decided on South Park.
After 4 episodes I realized that Mark still wasn't home, and he was supposed to be here an hour and a half ago.
I jumped up and made my way to the door.
"Jack! Where are you going?"
"Mark was supposed to be here an hour ago!" I said.
"I'll go with you." Wade said.
Everyone else decided to stay in case he came home.
Wade was driving slowly around.
"How far could he have gone! He can barely walk on his own!" I said with frustration after going for about 15 minutes.
Wade turned the car around and pulled to a small park.
"Where are we?" I asked.
"Mark comes here sometimes when he needs air." Wade said.
We walked around the park and I sat down on a bench when we found no sign of Mark.
Wade could sense my panic and hugged me.
"He is fine Jack. This is Mark we are talking about." He said.
I looked at the ground when something caught my eyes.
There was something carved into the bench
It was a heart with a small
'Sean M' in it.
I smiled.

Mark was here...
But where is he now...?