In 1943, Ortiz became a member of the OSS. On January 6, 1944, he was dropped by parachute into the Haute-Savoie region of German-occupied France as part of the three-man "Union" mission, with Colonel Pierre Fourcaud of the French secret service and Captain Thackwaite from the British Special Operations Executive, to evaluate the capabilities of the Resistance and train the Maquis du Vercors in the Alpine region. He drove four downed RAF pilots to the border of neutral Spain, before leaving France with his team in late May.