The agency is hired by Valerie Ferrar to investigate the death of her father, Les Ferrar. He, who made a living betting horses and often winning in knowing all the horses on the circuit inside out, was killed by being accidentally trampled by a stallion in the track stables. Valerie is almost certain he was murdered as he, knowing horses, would not put himself in a position of danger concerning horses. The Angels and Bosley decide to go under various covers at the track, with a possible murderer being a number of track regulars: stable owner Carter Gillis; trainer Thad Roper; training boy Kevin Ryan; and Gates, a stable hand. They believe that Les' death has something to do with a horse switching scheme, namely with a horse named Perdition who none of the regulars seem to have any faith in, but who seems to run like a dream. They know that the horse at the track claiming to be Perdition, isn't. Even if they are able to find Perdition, they have decide how to play it out as they still have to find Les' murderer first and foremost.
—Huggo