After extremely cloudy weather for days on end I was both shocked and delighted to see the clouds break late this evening (July 4/5th). Within minutes the entire sky was crystal clear with the transparency 8/10. I was talking with John Mc Connell over the phone while scanning the bright twilight sky with the naked eye and at 23.10 BST I spotted a strange form 15 degrees above the NW horizon. It was a single extremely faint (type 1) white whirl at a very high angle with respect to the horizon. It looked like a strange NLC worm dangling through the twilight which was very advanced at this stage. Through 10X50mm binos I could see its sharp form with twists and irregularities and with a very thin dark shadow band on its eastern flank. By 23.30 the 'worm' had grown into a very long large scale whirl extending across the N-NE sky however there was a second whirl some 40 degrees high across the NW-N sky. The two forms crisscrossed low in the sky forming an NLC 'X' shape. Clouds covered the display soon after. I managed to squeeze 30 minutes of comet hunting in the NW sky then the cloud cleared again before dawn but by now there were no NLCs to be seen and I assumed it rapidly faded from view. Over all I seen type IVc and after a look at my images I could detect possible numerous very long type IIB bands.