Kammala wannan jumla: A shekara ta 1945, kusa da
a karshen yakin a Turai, Smyth ya shiga aikin sirri na Alsos. Masanin kimiyyar mai shekaru 50 ya tashi zuwa Turai don taimakawa wajen tantance yanayin shirin makaman nukiliya na Jamus da kuma kama kayan aiki da ma'aikata. A wata masana'antar da aka yi watsi da ita a Celle ya gano wani na'urar da ake amfani da ita don wadatar da uranium, wanda ya ba da himma ga kokarin neman Paul Harteck. Smyth kuma ya farautar Paul Herold, Eberhardt Elbel, da kuma Farfesa Osenberg. An ba Smyth lambar yabo ta 'Yanci don aikinsa tare da Alsos.