A growing cluster of unexplained illnesses among US diplomats forces a response from the government. One CIA field agent refuses to let the issue be ignored, becoming both advocate and investigator. As more reports surface, the agency sends a medical expert to assess the situation on the ground.

What happens next sends shockwaves through the case. In a story filled with doubt, deflection, and delayed decisions, the line between investigator and victim suddenly begins to blur - raising new questions about the nature of the threat, and whether anyone is truly safe.

New episodes will be released weekly, wherever you get your podcasts, but if you are in the UK, you can listen to the latest episodes a week early, first on BBC Sounds.

Havana Helmet Club is written and presented by Jennifer Forde and Sam Bungey

Havana Helmet Club is a Yarn production for Radio 4 and BBC Sounds