Across
8. Norse literature found, oddly, in Shanghai (4)
9. Disunite! (5)
10. Measure a code (4)
11. Almost sooner than expected (6)
12. Six a.m. in a stupid line with everything spinning around (8)
13. Move away to join the legion (6)
14. One pitch thrown by the sound of it (8)
15. Leaves to fix a leak (4)
16. Sam says it's no longer due (5)
17. Thompson at Howards End has Mame in a tizzy (4)
19. Peggy moves on board to win 'B' race, big deal (8)
22. He may play a fiddle or a fish, unless he's tipsy (6)
23. This sign is worse for a psychic's visions (8)
25. Artoo's follower takes Sandra as well (6)
26. Give a hand to Leadbetter (4)
27. Rent easel (5)
28. Lit a match to follow one's movements (4)
Down
1. Transplant me a lilac for a flowery shrub (8)
2. A fracture along the forehead (8)
3. Move fast before that there author (6)
4. Entry for a couple perhaps (4)
5. Some native Americans fish around a dilapidated mine (8)
6. Fodder for a Mexican story about a mother (6)
7. Partly overwhelmed, I circumvent a great Italian family (6)
14. It sounds like part of what we all pray for (5)
16. Look at ease as he'll bring scallops home (8)
17. Some have wished to swap them canines (8)
18. 101 neon M&M's to jog the memory (8)
20. Hairy concoctions set off sirens (6)
21. Take offense if empty bazaar not working (6)
22. Once divided it's erased in a fashion (6)
24. Boom box (4)