Renault shows up at Rick's as the two prepare to proceed with their dastardly plan to get Victor arrested as he's trying to escape.
Renault makes himself scarce when a car pulls up outside, and Ilsa rushes in. She's concerned that Victor still thinks she's leaving with him, but Rick assures her everything is going to be just fine.
Like those words ever put anyone at ease.
Just as Rick is about to hand over the letters to Victor, Renault announces himself and places his man under arrest, just as planned. Or does he?
Ilsa runs to Victor; Rick sees it and something inside him shifts gears.
Suddenly, Rick's pointing a gun at Renault and telling him to sit down with his hands on the table.
Next he orders him to call the airport and let them know they are to give two people leaving for Lisbon absolutely no trouble. Renault, possessing no principles he feels are worth getting shot over, complies.
Or does he? Renault isn't actually calling the airport—he's calling Strasser. But Rick doesn't know that. Smooth move, Renault.