From The Daily Mail:
Police have sent samples to Porton Down as they probe a major incident after a couple in their 40s were exposed to an unknown substance, it has emerged...
Images from the scene showed a police presence in Muggleton Road, Amesbury, where the pair were found unconscious inside a property on Saturday, while a nearby Baptist church appeared to have been cordoned off.
The address is thought to be on a new housing development on the southern edge of the town, which lies close to Stonehenge...
Here's the bit they missed: "Four-bed detached houses on the estate sell for £410,000".