Call of Cthulhu: Operation Downslope

A group of British commandos infiltrate occupied France to rescue a defecting scientist in a mountain top command post and research lab. In order to save the scientist, they must take out a team of German soldiers and pose as them. Once inside, the team discovers the Nazis are tapping into unnatural forces to further their war efforts. Can the commandos carry out their mission even though they weren't briefed?