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
Editor: Guy Crossman
Story editing: Mike Ollove Producer: Larry Ryan
Sound designer: Merijn Royaards
Additional mixing: Peregrine Andrews
Theme music: Tom Pintens, with additional music composed by Merijn Royaards
Fact checking: Stanley Masters. Additional reporting: Isobel Sutton, Pascale Hardey Stewart and Stanley Masters
Archive producers: Miriam Walsh and Helen Carr
Production executive: Kirstin Drybrugh
Editorial advisor: Jesse Baker
Commissioner: Dylan Haskins
Assistant commissioners: Sarah Green and Natasha Johansson

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