Siemen Rühaak

as Boy Kröger

as Fritz

as Ulf "Piet" Petersen (1 episode)

as Marcus

as Fritz

as Franz Brosi

as Franjo Bauer

as Piet Starck (1 episode)

as Ted

as Dr. Ingmar Kehl (1 episode)

as Heribert Fabeck (1 episode)

as Jörg Hienzsch (1 episode)

as Prof. Weingarten (1 episode)

as Gordon Dempsey

as Nick (1 episode)

as Bernd Jung (1 episode)

as Dr. Udo Schönbach

as Berger (1 episode), as Prof. Hechtel (1 episode)

as Prof. Dr. Peter Derichs (1 episode)

as Dr. Jansen (1 episode)

as Oliver Miller

as Dr. Richard Schuhmann (131 episodes)

as Carsten Grünert (1 episode)

as Erwin