Theater by the Blind presents Agatha Christie’s The Unexpected Guest. This is the playwright’s most romantic mystery. A man runs his car into a ditch in thick fog, comes up to a house to get help, and finds a dead man in a wheelchair and a beautiful woman with a smoking gun. Audiences can guess the murderer at intermission and may win a prize. Detecting who’s blind, visually impaired, or sighted will be much harder.