Nine million Americans live near an orphan oil and gas well. These wells have no owner and they were never sealed, so they’re leaking out tons of methane and deadly gases unchecked. Some are 150 years old and were lost with time. Finding and plugging them with cement can get costly, and most states don’t have the funds to do it. But with $4.7 billion in funds to address this problem passed with the infrastructure bill, there’s renewed hope. We follow one ex-oil executive and his team as he hunts down and plugs forgotten oil wells.