A man is serving a life sentence. He has been plotting his escape for almost 20 years.
The left and right edges of the wall are the same edge, which is why they are drawn open. Each row holds two across answers, and one of the two may run off the last column and carry on at the first. Bars mark where answers begin and end, including the bars on the open edges.
In every column exactly one down answer is too long for the space the bars allow it. The clue defines the whole word and the bracketed number is the whole word's length, but one letter is chipped out before the answer goes in. Each chipped letter falls straight down its own column into the yard below. Read the yard from left to right for the final answer (11).
Two rows and four columns of the filled wall spell a woman's name in a block. Draw her frame around it.
Start two squares below that frame's left-hand edge and move one square at a time to a neighbour, never using a square twice. One route spells a parting instruction (3,4,6). It breaks out through the bottom edge, and where it leaves is the way out.
Two answers are proper names.