Stuck on two interconnected clues.The 5th letter of the across clue coincides with the 5th of the down clue.22ac.Crazy,cold driving mist precedes Brtiish downfall(10).?RAI??RA?N. 13d. Support time in infirmary,for some it has to go(7,2 words)?TI??B? Thanks in anticipation for any help received.