The Democrats’ impeachment inquiry is all about Ukraine. And Ukraine is all about natural gas. Most Russian gas sold to Europe flows through pipelines crossing the nascent democracy. The gas sector is where a huge amount of Ukraine’s wealth comes from—and, by extension, its corruption. And the country’s huge state-owned natural-gas company, Naftogaz, finds its way into smackdowns between oligarchs and international energy stand-offs.

That’s why Energy Secretary Rick Perry hovers in the background of the impeachment saga. As Texas governor, he earned the affection of America’s oil and gas barons. And as energy secretary, he’s pushed for reforms to make Ukraine friendlier to Western investment.

In the process, he’s encouraged the Ukrainian government to turn to at least two Americans for advice: one man who donated to Perry’s inaugural campaign, and another who used to advise one of Ukraine’s most Russia-friendly politicians. So who are they?