Black Holes and Firewalls: Can We Take Nothing For Granted

If the formation and evaporation of a black hole preserves quantum information, then the horizon is a special place, unlike empty space everywhere else. This conclusion is dramatic, as it appears to contradict the equivalence principle. I will discuss proposals for how to avoid a "firewall" at the horizon, and why they fall short. The equivalence principle may nevertheless be upheld, if firewalls can be understood as a failure of the vacuum state to emerge dynamically.