- "Dernier. My people were resisting the Nazi occupiers in Marseille."
- ―Jacques Dernier
Eventually, Dernier was captured by the Germans and sent to work at the HYDRA weapons facility in the Austrian Alps. In October 1943, he met other Allied POWs: Bucky Barnes, Dum Dum Dugan, Gabe Jones, and James Montgomery Falsworth. With their help, Dernier was able to mix chemicals to corrode machinery and cause an accident that killed HYDRA Colonel Lohmer. However, Dernier and the others had their rations withheld from them for a week. Dugan provoked a fight with Dernier when he jokingly said that the French never tried to defend Paris against the Germans.
In November 1943, when Captain America single-handedly assaulted the facility in which he was prisoner, Dernier, along with his companions, broke free and wreaked havoc on the HYDRA agents. Dernier teamed up with Jim Morita and took a HYDRA gun which was powered by the Tesseract; it proved to be incredibly powerful and helped them escape. Dernier joined with the other POW's and eventually arrived back to United States military base in Italy.
Shortly after their break-out, Dernier and his comrades were invited to join a special operations unit led by Rogers himself. Dernier, after a brief conversation in French with Gabe Jones, happily accepted. Along with the other Commandos, Dernier took part in many assaults against HYDRA, until the end of the War. During one assault, Dernier single-handedly destroyed a HYDRA Mini Tank by running into its oncoming path and placing a bomb under its manifold. He stood in the road and watched as it exploded, turning to the other Commandos as if it was easy.
- Expert Marksman: After joining the French Resistance, Dernier became proficient in firearms usage. After being freed by Captain America during the Liberation of Allied Prisoners of War, he wielded a Tesseract-powered HYDRA gun with relative ease, killing multiple HYDRA soldiers with it.
- Explosives Expert: Being considered the explosives expert of the Howling Commandos, Dernier had the ability to single-handedly place a bomb under the manifold of a HYDRA Mini Tank and destroy it.
- Sten MkII SMG: Dernier carried this submachine gun as his weapon of choice, and he used it during the Howling Commandos' raids on HYDRA facilities.
- M1A1 Carbine: Dernier switched his weapon to one of the standard firearms of the United States Armed Forces when he broke through the doors of HYDRA Headquarters, as part of the Strategic Scientific Reserve's assault on the base.
- In the comics, Dernier was referred to as "Frenchie". This could be his nickname in the movie, just like Dum Dum, or Bucky.
- His year of birth makes him the oldest member of the original Howling Commandos.