A teenager hides a vape pen in her backpack, the nicotine satisfying a craving she does not remember developing, and she tells herself she can stop anytime while knowing that every attempt to quit has lasted less than a day. A construction worker takes prescription opioids for a back injury, follows the dosage instructions perfectly, and discovers months later that stopping the medication triggers withdrawal symptoms that make him understand for the first time why people do desperate things, while the injury that started this journey healed long ago.