For all things Paris, President Donald Trump’s go-to guy is Jim.

The way Trump tells it — Jim is a friend who loves Paris and used to visit every year. Yet when Trump travels to the city Thursday for his first time as president, it’s unlikely that Jim will tag along. Jim doesn’t go to Paris anymore. Trump says that’s because the city has been infiltrated by foreign extremists.

Whether Jim exists is unclear. Trump has never given his last name. The White House has not responded to a request for comment about who Jim is or whether he will be on the trip.

Trump repeatedly talked about the enigmatic Jim while on the campaign trail, but his friend didn’t receive widespread attention until Trump became president. For Trump, Jim’s story serves as a cautionary tale – a warning that even a place as lovely as Paris can be ruined if leaders are complacent about terrorism.

Jim’s biggest moment in the spotlight was during a high-profile Trump speech in February at the Conservative Political Action Conference in Maryland. Trump explained that Jim “loves the City of Lights, he loves Paris. For years, every year during the summer, he would go to Paris. It was automatic, with his wife and his family.”