Junák was abolished by force and Scouting prohibited by German State Secretary Karl Hermann Frank during the Nazi occupation of Czechoslovakia on October 28, 1940.

[1] Plajner was an RNDr., the Czech doctorate in natural sciences, specializing in math and physics at Charles University in Prague.

[citation needed] Plajner took part in building Defense of the Nation (cs:Obrana národa) and in other resistance organizations.

He again joined the Czech resistance to Nazi occupation and cooperated with guerrilla brigade "Jan Žižka".

[citation needed] After the war Plajner received several honors and Junák started to work again in 1945, but in 1948 was included in the Socialist Youth Union (cs:Socialistický svaz mládeže, SSM), the Czechoslovakian Communist youth organisation, and dissolved in 1950.