An unwelcome surprise may greet fans of Slow Horses star Gary Oldman and talkshow host John Oliver, with the two TV legends appearing to be several rows back from the front.

A celebration of the purebred horse, “the largest show of its kind outside of Spain,” according to the press release, with rounds of traditional Spanish horse dancing, 5 p.m. Sept. 12-14. Doors, 3 p.m ...