When you don't want a cop

 Mrs. Waddington considered that in this instance her ally was carrying caution too far. She turned on him with a snort of annoyance: and, having turned, remained staring frozenly at something that had suddenly manifested itself in his lordship's rear.

This something was a long, stringy policeman: and though Mrs. Waddington had met this policeman only once in her life, the circumstances of that meeting had been such that the memory of him had lingered. She recognized him immediately: and, strong woman though she was, wilted like a snail that has just received a handful of salt between the eyes.

(from The Small Bachelor, by Sir Pelham Wodehouse)