Puzzled about the wordplay on these - any help please? 1d is 'tabu'. How is this reached from 'Heartless killer surfacing is ostracised'? I can see 'tabu' = 'ostracised' but where's the heartless killer? 22a is 'water-softener' Clue: 'Quality's more frequently found in domestic appliance (5-8)' How come 'water' stands for 'quality'?