[2][3] For the first time in five years, pilot Jim Brennan (Errol Flynn) flies to Istanbul, Turkey, but is immediately brought to the office of customs Inspector R. P. Nural (John Bentley) who suspects him of diamond smuggling.

At the café, Jim sits at his regular table and recalls the last time he was there, sharing a drink with German tourist Stephanie Bauer (Cornell Borchers), a beauty with whom he falls in love.

She accepts his proposal, but back at his room, the couple encounter Paul Renkov (Werner Klemperer) who is looking for the diamonds.

The police find Jim, and at headquarters, Nural tells him that Aziz was murdered likely due to his role in a shipment of stolen diamonds smuggled in a bracelet.

Jim knows the married couple in his old room are in danger, and goes to the hotel, but is amazed to see Stephanie there.

Leaving the room he allows himself to be captured by Renkov and taken to an abandoned warehouse where Darius has already kidnapped Stephanie.

Rushing to the airport, they see that Jim is caught with the diamonds although Nural decides to let him leave the country.

As the aircraft takes off, her husband sees Stephanie's reaction and with the inspector's help, Jim is ordered to come back to Istanbul as someone wants to reunite with him.

[9][10] Flynn later wrote "I thought the film was to be made in Turkey, but it turned out I must go back to Hollywood In the States, people who saw me again on the screen said I looked dissipated.

[14] Music and lyrics by Victor Young and Edward Heyman Sung by Nat 'King' Cole Music and lyrics by Jay Livingston and Ray Evans Sung by Nat 'King' Cole Written by Milton Rosen and Everett Carter Written by Henry Mancini and Frederick Herbert Written by Milton Rosen and Everett Carter Written by Milton Rosen and Everett Carter Music by Henry Mancini Lyrics by Jeff Chandler Bosley Crowther in his review for The New York Times, described Istanbul, as basically mediocre.

[17] Filmink magazine said "the script is full of echoes of Casablanca – it’s set in an exotic city, is about a shady hero who is (surprise) deep down a goodie and has a long-lost love, a black pianist friend and a friendly rivalry with the local chief of police – but they only serve to remind the viewer of what a better movie that was.