Born in Belarus, raised in Kazakhstan and schooled in the ways of fracking in the shale fields of America, Oleg Tolmachev arrived in Kyiv 13 months before the bombs started falling.

The mandate he had been given was a crucial one: Apply the complex drilling methods he learned in the U.S. to the tight rock formations that dominate much of the Ukrainian oil and gas landscape and, in the process, help wean the country off Russian energy. Naftogaz, the company that hired Tolmachev to oversee production, is the nation’s dominant gas supplier. If the lights are going to stay on and homes are to keep warm in the harsh Ukrainian winter, Tolmachev is going to have to find a way to keep the gas flowing.

So when the explosions marking the start of the Russian invasion jarred him awake early Thursday morning, he knew what to do. He grabbed his stash of cash, his Garmin InReach satellite messenger and his Swiss Shepherd dog Maya, and pointed his SUV west toward Lviv, the Ukranian city along the Polish border that Naftogaz top executives designated as a command center if fighting broke out.