

Not being able to implement his invention in his home country, engineer Arrowsmith, the author of the patent for ore flotation, goes to the USSR to work at one of the flotation plants, where he soon learns that a group of Soviet engineers is conducting similar work.
Boris Livanov
Dick Arrowsmith
Boris Svetlov
Layons
Maksim Shtraukh
Samuel Wolfe
Andrei Abrikosov
Engineer Nikitin
Sergei Tsenin
Sazonov
Viktor Stanitsyn
Bill Steer
Oswald Glazunov
Rector (uncredited)
Vera Maretskaya
Comrade Olga
Vladimir Uralskiy
Gostev
Dmitriy Kara-Dmitriev
Bistayev
Aleksey Dolinin
Gaydar
Sergey Tikhonravov
Garreth