SOLUTION TO PUZZLE No. 8600:

ACROSS: 1 Before all; 6 Silas; 9 Siren; 10 Cha-cha-cha; 11 Laughingly; 12 Blue; 14 Crayons; 15 Telling; 17 Oversea; 19 Creeper; 20 Earn; 22 Adroitness; 25 Offhanded; 26 Emile; 27 Nasty; 28 Parakeets.

DOWN: 1 Basil; 2 Formulate; 3 Ranch house; 4 Ascents; 5 Leaflet; 6 Soho; 7 Local; 8 Scavenger; 13 Blue streak; 14 Close down; 16 Imprecise; 18 Added up; 19 Chowder; 21 Ruffs; 23 Sheds; 24 Lady.