2: Mortified humans - fifty per cent felt great pity (7)
5: Bolt I have inserted in right frame (5)
6: However, you expect trouble at first (3)
8: Study a French instrument - it's a puzzle (9)
10: Bend in the middle and wind back (3)
12: Messages transmitted about a mile (1-4)
13: The day ends with an unpleasant ancestral line (7)