chesswise

A ply is half
a move in chess. 
A trade takes two 
plies - one move, 
yes. To ply one's 
trade means sacrifice 
- unless you nip,
and they don't bite!
But if so, check six 
moves ahead! They 
probably saw some
move instead, and if
you missed it, you'll
get pawn'd.
Or rook'd,
or queen'd
or dead, 
or trodden
on.