More than two years after British voters approved a measure to withdraw their nation from the European Union—a gigantic undertaking with no roadmap of any sort —Prime Minister Theresa May unveiled a plan: essentially, that the U.K. would remain in the European customs union, participating in trade with the E.U. and remaining subject to its trade policies, but exit the political process of the E.U. The deal was seen by some as the worst of both worlds, and several cabinet ministers resigned; May could well lose a no-confidence vote in the immediate future. David Remnick talks with the London-based staff writers Sam Knight and Rebecca Mead about the ongoing challenges of Brexit.