Across: 1 Matilda 5 embassy 9 whale 10 backstage 11 non-starter 12 old 14 Indo-European 18 cairn terrier 21 sky 22 parliament 25 onlooking 26 house 27 Martian 28 torrent.
Down: 1 mewing 2 trains 3 lieutenant 4 amber 5 exchequer 6 busy 7 sea power 8 yielding 13 foregather 15 operation 16 ice storm 17 bicycler 19 ferule 20 street 23 light 24 Loki