Oh my, might STX have made a dirty cop thriller?

Not Chadwick Boseman. He’s the detective sent to figure out why eight police officers died in a drug raid, and kill or catch — in that order — the people responsible.

What will he discover as he closes Manhattan’s “21 Bridges,” shuts down subways and ferries, swamping the island with a “flood of blue” in this manhunt?

Sienna Miller, Keith David and J.K. Simmons also star in “21 Bridges,” which opens July 21.