For years, fentanyl has flooded into the American drug market, driving a surge in overdose deaths across the country. Other drugs, like cocaine, are increasingly tainted with the synthetic opioid. We spoke to advocates Theo Krzywicki and Kalie Shorr who say a tiny test strip can help people avoid fentanyl, and WSJ's Julie Wernau explains why fentanyl is showing up everywhere. Further Reading: - Fentanyl Test Strips on the Dance Floor? Partygoers Face New Reality  - Three New Yorkers Ordered Cocaine From the Same Delivery Service. All Died From Fentanyl.  - The Fentanyl Crisis  Further Listening: - Purdue's $4.5 Billion Opioid Settlement Got Thrown Out. Now What?   - States Got Hooked on Tobacco Money. Are Opioids Next?   - Two Days of Reckoning for Opioid Makers   Learn more about your ad choices. Visit megaphone.fm/adchoices