Boris Livanov
(Dick Arrowsmith)
N. Golitsyna
(Ethel)
Maksim Shtraukh
(Samuel Wolfe)
Boris Svetlov
(Layons)
Sergey Tikhonravov
(Garreth)
Viktor Stanitsyn
(Bill Steer)
Andrei Abrikosov
(Engineer Nikitin)
Sergei Tsenin
(Sazonov)
Aleksey Dolinin
(Gaydar)
Dmitriy Kara-Dmitriev
(Bistayev)
Vera Maretskaya
(Comrade Olga)
Vladimir Uralskiy
(Gostev)
Leonid Kulakov
(Rakitin)
Oswald Glazunov
(Rector (uncredited))
Ivan Lavrov
(Professor (uncredited))
Lyudmila Glazova
(Felice (uncredited))
Marta Aleschenko
(John's wife)
Timofey Remizov
(Laboratory worker (uncredited))
Eva Milyutina
(Arrowsmith's guest)
Ivan Chuvelyov
(Arrowsmith's guest)
Leonid Obolensky
(The reporter (uncredited))
Weyland Rodd
(The worker (uncredited))
Eduard Gunn
(The provocator (uncredited))