The Calculus Affair (1956)

In the tense climate of the Cold War. This new adventure takes Tintin back to Syldavia and Borduria. After inventing an ultrasound machine, Professor Calculus is kidnapped.

Jolyon Wagg, an insurance sales rep, makes his entrance in this story, and will prove to be a perfect nuisance.

A Thirillin chase, surprises, old friends getting back together, headlong fights... all this for a stake which seems limited to an ordinary umbrella: this is probably the most "detective-like" episode of the series.