The scientist Barbikian has developed bacilli that can cause irresistible laughter in people to whom they are inoculated. He decides to use his discovery to prevent any possible conflict in the world.
However, due to misinformation about the nature of his discovery, numerous emissaries of foreign powers try to seize the vials containing these bacilli. Barbikian finds himself forced to evade various ambushes organised by American, Russian, French and Chinese agents, who team up in an attempt to obtain the mysterious invention.
Barbikian finds himself surrounded by his pursuers, but a sudden accident causes some vials containing the exhilarating bacilli to rupture. This causes the evil intentions of the foreign agents to turn into general roaring laughter, putting an end to their plan and ensuring peace.