For 20 years, someone stocked a Coke machine on Seattle’s Capitol Hill with obscure, sometimes discontinued drinks such as Grape Fanta, Mountain Dew White Out, Hawaiian Punch, and raspberry Nestea Brisk. The price was 75 cents, and each button read simply “? MYSTERY ?”

The machine stood in front of Broadway Locksmith on John Street, but the locksmith claimed to know nothing about its operator. When the city passed a tax on sugary drinks in January 2018, the machine raised its price to $1.00. Six months later, it disappeared, leaving only a message on its Facebook page: “Going for a walk, need to find myself. Maybe take a shower even.”

It hasn’t been seen since. Do machines take walks?