The Phantom of the Turf.

When a wealthy recluse apparently commits suicide, his trusted friend John Nichols (Rex Lease) is put in charge of the estate. Nichols is ordered to locate the dead man's long-lost son and daughter and inform them of their legacy. The two beneficiaries turn out to be the owners of a run-down racetrack. Falling in love with the daughter (Helene Costello), Nichols tries to rejuvenate the track with a high-stakes horse race.