[KC] The KNIGHTMARE card

[Kevin dylo dylo]

Greetings,

My apologies if I've missed something, and certainly for being dense.  But 
it's always good to clarify.

Situation: I have DOUBLE KILL. I want to use it to remove my opponent's 
Royal Knight, but I suspect (correctly) that he has KNIGHTMARE. I choose to 
try taking the Royal Knight with a pawn, instead, and do nothing with my 
cards. He plays KNIGHTMARE. I rejoice. I now want to play DOUBLE KILL, but 
we're not sure that I can.

KNIGHTMARE says that Your opponent's move is canceled. He must make a 
different move, with the same piece or another one. IF HE USED A CARD, he 
may take it back.

The FAQ says
A. FOG OF WAR is the only card that cancels another card. KNIGHTMARE! et al. 
cancel a move and give the victim the option of retrieving his played card, 
if any. He may play the same card, or a different one, as long as his move 
is different.

So, we're thinking that since I didn't play a card, I can't now. Is that 
correct?