cant find the single black switch wire in the ceiling blocks?

ive fitted 9 low voltage flushed spots in my extension off of the kitchen,ive wired up neatly but as i was just about to wire the final ceiling centre light i noticed the wires were in block connectors.i have 2 blacks and 2 reds and 2 earths going in a three block connector,but no switch wire to be seen although i do have a single red thats been stripped out of its sheath and fed into a single block connector. now ive changed the blocks for a 4 way junction box left out the red as i dont know wot it is, wheres me bl**dy single black switch wire. i guess the feed is coming from the kithen the other cable feeds the void light under the extension, i think!.is one of these a switch wire, but it cant be, could it help, ive just wired up the same spec in the kitchen and fitted a single dimmer switch and it works fine first time but clearly it had a single black switch wire that is sleeved red.any help please i bet its under another joist, ive just over boarded the ceiling in both rooms.your expertease please.dully.