13 across: With last of business covered, take off for recess (5).
This was the first clue I wrote in, seeing the 's' and the ape = take off, but I'm not happy with the parsing of my answer 'apse' = recess. Why is the 's' in the 'ape' rather than the other way round? A simple point, but I would be pleased with some elucidation. Thanks in advance.