Some debate over whether this is a Biggles book or not as it is a collection of six adventures, only one of which is about Biggles.

The Biggles story (Thunder over Germany) has the usual suspects follow up on a lead from a schoolboy to destroy a secret German fuel depot in the Black Forest. In a hair-raising daytime attack the team fly over Germany and the schoolboy, acting as navigator, leads them straight to the secret depot. They then have an incident packed flight home before all landing safely.