Tavleen Singh’s first novel begins with a familiar kind of silence: the hush after a star’s third flop, when the lights are still on but the audience has begun to leave. Amit Singh, Bollywood’s once-infallible leading man, is forty, lonely, and studying his reflection for the first new lines. Then a phone call arrives from Naresh, an old-school friend now building a political party to challenge a country drifting toward religious autocracy. Amit accepts, partly for India, partly because cinema has stopped applauding.

The Actor moves between Bollywood’s gilded rooms and the rough-edged India that Amit has never needed to see. On the campaign trail, he visits villages where garbage, poor schools and fragile livelihoods are the daily weather. He hears about lynchings, Muslim fear, caste prejudice and political compromise.…