Millions staffer Mark O’Connell immersed himself in the “transhumanist” movement for more than a year, checking in on such characters as Zoltan Istvan, the quixotic U.S. presidential candidate perhaps best-known for driving a coffin across the country. O’Connell’s book, To Be a Machine, which details dreamers like Istvan envisioning human existence liberated from the outmoded confines of the human body, publishes this month.