Failing to achieve its objective, the campaign was called off on 19 August 1944 after a request from the Soviet high command which was about to launch a major offensive against Romania.

[3][4] In the aftermath of King Michael's coup on 23 August 1944, the German troops from Bucharest were instructed by General Constantin Sănătescu, the new Prime Minister of Romania, to retreat towards the Hungarian border.

[5][6] As the German raids continued, the Allied prisoners were released from the Timișul de Jos and Bucharest POW camps and allowed to hide in the trenches outside, being also given some firearms to defend themselves.

[4] At the same time, a delegation of the prisoners requested General Racoviță, the War Minister, that they should be organized into a combat unit under Romanian command to fight the Germans.

[4][10] On 24 August, Gunn met with Valeriu "Rică" Georgescu, a former collaborator with the British Special Operations Executive who was released from prison on the same day.

[4][11] Georgescu also managed to contact the Cairo command via radio and requested an urgent airstrike over the German troop positions at Băneasa and Otopeni.

At the same time, Georgescu introduced Gunn to Prime Minister Sănătescu, General Racoviță, and Iuliu Maniu, the leader of the National Peasants' Party.

[12][13] With the Germans cleared out and the bombing raids stopped, Rică Georgescu took Lt. Col. Gunn to the Popești-Leordeni airfield where they met up with Captain (Cpt.)

[17] After landing, Cantacuzino taxied over to some base personnel and asked for a screwdriver which he then used to open the radio compartment of the airplane and retrieve Gunn.

After receiving a signal from the ground, and after the escort fighters scouted the area, the B-17s were to land, unload the equipment and personnel, take a maximum of 10 POWs if any were present on the airfield, and take off immediately.

[18] The rest of the mission went as planned, with Cantacuzino sending the signal that the airfield was safe, the escorting Mustangs then transmitted the message which was received by a weather airplane over Yugoslavia and further relayed to Bari.

The two B-17s transporting the OSS personnel under the command of Colonel George Kraiger landed safely in Romania and were greeted by Rică Georgescu, who by this point was assigned as State Secretary for the Ministry of Economy.

[22] As some ex-prisoners were scattered around the country with the help of the locals, radio broadcasts and press releases were sent out with instructions that they needed to report to Hotel Ambasador [ro], the headquarters of the OSS mission,[21] for evacuation.

To secure the transport of prisoners to the airfield, Secretary Georgescu arranged with Colonel Victor Dombrovski [ro], the Mayor of Bucharest, the requisition of some 57 buses from the capital.

[5][23] On 31 August, as Soviet troops were entering Bucharest,[5] the first 38 B-17s, all from the 5th Bomb Wing, flew from their bases in Italy to Popești-Leordeni in four waves, returning fully loaded with POWs.

[27][28] A monument honoring the American prisoners from Romania was built in the Memorial Park of the National Museum of the United States Air Force.