Possible Clues:

• Difficult to describe
• Hard to find English active around us
• Following end of chase, evil US criminal is hard to find
• First of clues missed out? Puck's hard to find
• Use live explosive that's slippery
• Use evil trick, being slippery
• Difficult to understand
• Hard to locate European, as it happens, going around America
• European charged outside America is difficult to catch
• Shifty