A starry thriller set in a kinetic, nonstop Manhattan, “Relay” races along with a hide and seek, cat and mouse scenario where you’re often not quite sure who’s chasing who.

It begins with corporate whistle blower Sarah Grant (Lily James) wanting to make a deal with her employer: She’ll forget – for a bundle of cash – about exposing the negatives in their new drug about to get a global launch.

Riz Ahmed’s Ash is the relay mastermind who will barter the deal, keep Sarah alive from reprisals and handle the sizable cash payment.

“A relay service machine was something that was created for the deaf and hard of hearing community,” Ahmed, 42, said in a virtual interview from London this week. “It’s a way for them to make phone calls. They would plug in something that resembles almost a fax machine or a typewriter and type messages to an operator. An operator would make the phone calls on their behalf and then relay the message back to them, which would appear as text.

“It’s not something that’s used so much anymore. But the interesting thing about it is that my character Ash is very much off grid, offline, trying to avoid being traceable by all the many people who’d like to find out who he is.

“So it’s a really interesting concept in that he uses this relay service because it is undetectable and untraceable due to a legal loophole.

“And that speaks volumes about Ash as well: Someone who keeps people at a distance, who’s guarded. A man of few words. The most animated personal relationship we ever see him in is with a member of the deaf community, where he’s not communicating with words, but American Sign Language” – a sequence that nods to Ahmed’s Oscar-nominated work in “Sound of Metal.”

“So the relay machine is central to the plot, but it’s also very symbolic about who this character is and how he uses intermediaries and masks to keep people at bay.”

What’s really rare here is how “Relay” gives jolting glances at the frenzied cityscape with Ash on the run.

“New York’s like a character in this movie and it was such a gift to be able to shoot on the streets with real people. (Producer-director) David Mackenzie welcomed that kind of frenetic, violent chaos into the movie, into the process. It’s the way he works: It’s fast. Point, shoot and you move on. No takes are the same.

“That’s a real joy. It means that nothing ever gets boring or predictable. I loved exploring the New York at night that I’ve always loved seeing in those classic thrillers.”

“Relay” opens on Friday

Riz Ahmed is a bribe broker in “Relay.” (Photo Heidi Hartwig/Bleecker Street)