cryptic crossword

ACROSS 21 Nobleman upset due to being excluded from activity (7,3) 6 Some earl or duke? Possibly (4) 8 Engineers getting caught, stuck in rubbish – we bring relief (3,5) 9 Cosy at home, confronting the enemy (6) 10 Written pieces, small bits with no heading (8) 11 Prayer in Latin translated by unknown character (6) 12 Thus house has no use in one part of London (4) 14 Imagine meal mostly containing fat? (7) 18 Infuriated and enraged, going berserk (7) 20 Brag as one involved in murder? (4) 23 Divine manifestation of a king at the rear of a tank? (6) 24 Earth disturbed by number seen as menace (8) 25 Men only half clever engaging a wise fellow (6) 26 Cinema must throw a shouter out (8) 27 Expanse of water providing a bit of summer entertainment (4) 28 Adopt a series of steps to disappear quickly (4,6)

DOWN 1 Pirates from whom may be heard rude affectation (8) 2 University head gathers 500 for briefing (6) 3 Chariot overturning in the land of Spartacus (6) 4 Princess meeting poet and pharmacist (9) 5 Huge number sing by way of conveying love (8) 6 Freedom from restraint that is minimal in Quito (8) 7 Old fellow in revolt is to become a Catholic (8) 13 US author may, from what we hear? (9) 15 Maybe Oxford poetry is all there is (8) 16 Historical leader of independence, guerrilla in imitation of others (8) 17 Sign of injury that is seen on street causing most dismay (8) 19 Not bad, we may become pessimistic (8) 21 Little woman coming to the Spanish house of prayer (6) 22 Like a racket that’s hurt, ear finally having to be covered (6)