Grace McDonald had to die so that Lark Birdsong could take her place and thereby save Grace's life. 

Grace and her partner, Edwina–affectionately known as Eddie–find themselves in dire straits when vile men with guns hunt them down and threaten their lives if they don't hand over the 17 million dollars they say the women stole. So much for trying to earn a little money with crypto currency!

So Grace McDonald had to die to save their lives.

Lark gets in her car in Toronto, Ontario, and heads south to the United States, her native country. When Lark stops at a Tim Horton's store for a break, then coffee and donuts, everything changes in harrowing ways. Lark went on a wild ride on a train she didn't get on and can't get off of. Why isn't she still in the ladies' room at Tim Horton's store? What happened on her way to Oklahoma? And why is her car on the American side of the border crossing while she's on the runaway train?

No actual death–or birth, for that matter–took place, but Grace McDonald's ashes are scattered, and Lark Birdsong is headed to Oklahoma to get help and hopefully save her and Edwina's life. The young women hope to live long enough to create a new beginning for themselves. Eddie's Aunt Minerva, in Guthrie, Oklahoma, seems to be the safest place for the women.