London has a synthetic opioid crisis. Why's only one woman investigating it?

When Caroline Copeland places the three small amber vials of synthetic opioids on the table, she starts to stiffen. “Don’t open them, please,” she says during our meeting in her Waterloo office. “We can take them out of this [the plastic wrapper], just don’t open the vials.” 

It was 2021, the pharmacology and toxicology expert tells me, when she began to notice it. In Croydon, drug users young and old were starting to drop dead, often in circumstances which made little sense to the clinicians treating them.