One day in Mr. Murphy's animal feed store Wilbur and Ed encounter Mr. McGivney, who is looking for a job. They are told that Mr. McGivney is a former groom who was dismissed for drugging a racehorse, Lady Sue, but has always maintained his innocence. Ed instinctively believes that Mr. McGivney is innocent and urges Wilbur to give him a job. But Wilbur is skeptical and refuses. Later, Ed contrives to secure Mr. McGivney a painting job with Addison, but Mr. Addison discovers his past.
As Mr. McGivney leaves, Wilbur has a word with him over the horse drugging, and is so impressed with Mr. McGivney's protests of innocence that he is won over. Wilbur figures the only way to find the true culprit is for Ed to speak to Lady Sue. But the problem is how to get the horses together. First, Wilbur tries to smuggle Ed in while disguised as a jockey and his horse, but the security guard blocks them. Next, Ed tries to teach Wilbur horse language so he can talk to Lady Sue himself, but Wilbur cannot get beyond a few letters. Finally, a remark from Addison gives Wilbur the idea of having Ed talk to Lady Sue by walkie-talkie.
The conversation with Lady Sue confirms Mr. McGivney's innocence and elicits a description of the true offender, Sam Morgan. But then Sam himself corners Wilbur and holds him at gunpoint. Wilbur uses the horse language he has learned to stall Sam while Ed uses the walkie-talkie to alert the guard. The guard arrives in time to hear Sam admit his guilt and arrests him.
Mr. McGivney is reinstated as groom. Wilbur and Ed are rewarded with free passes to the races, but Ed goes one better - he secures a date with Lady Sue.