The observant Mr Keen notices a dog that has been tied up, and leaping towards a window. What does it mean? The dog seems pacified once someone takes an interest in him. Mr Keen interviews the lady who lives in the house where the dog is, but he isn't her dog.

Mr keen takes the dog in as he contemplates over his missing owners. At the same time, Mr Keen gets the attention of a couple rough characters. What's happening here? How do all these elements come together? Need more clues? Ride along with Mr Keen as he keeps up the search.

The trail leads from cabbies, to horse tracks, to a carnival. When the dog and master are reunited, Mr Keen realizes that he isn't just in trouble, but there's real danger for his life.