1: Nixon's engaging Guevara in scraps (7)
4: Immerse in massive sound (7)
8: Martyr fighting segregation (5,6)
10: Plan to return with woman (3)
11: Cant this band collect any moss? (7,6)
12: at peoples uptown bar for starters? (3)
14: Feeling threatened, suggested concealing identity (11)
16: Clearances for the first couple of characters to find answers. (11)
19: Begins seeing another divorcee? Deplorable. (3)
21: Fling an item of furniture (3,5,5)
24: Now Elton heard California's big one (3)
25: E.g., told story about cave-men (11)
26: Declare leniency even heartless to be this! (7)
27: Iridescent stone contains quirk having to do with vision (7)