The group was formed in 1984 around the young punk rocker Petr "Sid" Hošek from Vyšehrad. Its premiere took place in August 1984 at a small festival in České Meziříčí, still under the name Plexis PM (punk music). In this initial lineup, Plexis played several successful concerts, including a sold-out double concert at Chmelnice. In 1985, bassist Marek Sibřina and guitarist Martin Bíňovec left, and Plexis continued as a trio, occasionally joined by Jan Haubert, the vocalist of Visací zámek, on guitar. They performed several other legendary concerts (Stará Lysá and Hudební parník Vltava - both in 1985), but after a concert in Opatov (1986), the band broke up. This initial lineup played punk in the style of The Exploited with simple humorous lyrics. The group was not heard of until the fall of 1988 (in the meantime, Hošek co-founded Do Řady! and played bass in Michael's Uncle, while Vitáček and Pavel Brož played in Visací zámek).