Got them all but can’t parse two:
27a. Last moment in episode with leaders in historic hostilities, once in control, retreating. (8,4)
Eleventh hour? Hh is leaders in historic hostilities, and event fits in somewhere, but can’t see it.
18d. Playwright in church sorry about end of talk on old verse (7). Chekhov? K is end of talk. Old verse is ov.
Thanks in advance.