I watched him get in to the yard, watched him cruise the fenceline in the back (and watched the other cats following him), then watched him leave.
When he started to climb the fence to get out, I called Brian over. He watched NP climbing the fencing over the pool pump and stepped outside to get a better view as NP monkey climbed to get out.
He said "this isn't good". After NotPanch was out of the yard, Brian went down to check out the fencing. And he came up with another place to add to. And there, NP will be able to get in, but most likely not out.
We'd really like him to stay in the yard. The other cats didn't seem to bother with him and it's way safer here than out there.