Cryptic Crossword No. 6

Across

1 Essay about object that's fashionable (6)
4 Capital containing a hospital for outcasts (7)
9 Very clever fish ain't at sea (9)
10 An island's turning black (5)
11 Follow headless queens around (5)
12 Show disapproval by taking carriage as a sort of practical joke (5,4)
13 So deep in thought one's absorbed - nobody will play with one (7)
15 A drink with a head (6)
17 Appalled - but helping to make Branagh a star (6)
19 Present course (7)
22 Two chaps like some medieval legends (9)
24 Philanthropist retiring for the good of France (5)
26 Letter from Greek graduate - it has four sides (5)
27 King accompanied by aerial artist (9)
28 Bird discovered by dramatist outside Los Angeles (7)
29 Nothing on listed building? (4-2)

Down

1 Bill allows some medicine (7)
2 England's first team takes both ends outdoors (5)
3 Self-indulgent life of fool upset by musical (5,4)
4 Crushing remark that's recorded (3-4)
5 After religious instruction, heaven appears unsafe (5)
6 Purple and gold mixture of beer and gin (9)
7 Look round shelter, being ready for bed (6)
8 Religious teacher with time for timid person (6)
14 Prescribed bedtime in lands abroad (6,3)
16 Latin verbal adjective given rude translation (9)
18 Kitchen order: stir in flour, possibly (7)
19 Clergymen preserve prodigal son? (6)
20 Cry in the field though little colleague is content (5-2)
21 Spanish-speaking area of city - except for a Portuguese-speaking city (6)
23 Sort of blume? Sort of bloom! (5)
25 Container containing a small container (5)