The “Reacher” set had some unexpected visitors while filming Season 4: former U.S. president Joe Biden and his son Hunter.

The Bidens and the “Reacher” cast and crew both happened to be in the same area in Philadelphia on Monday, leading to one of the most surprising crossovers of all time. “Reacher” star Alan Ritchson posted photos of himself posing with Joe and Hunter Biden on Instagram Tuesday morning.

“So our ‘Reacher’ set got in the way of these legends,” he wrote. “Was a privilege and honor to meet the Biden family. They couldn’t have been more lovely. Kind, joyful, gracious and present. We chatted briefly about simple stuff, like string theory and quantum entanglement. Then Joe beat me at arm wrestling. All in a day’s work.”

According to CBS Philadelphia, the Bidens ate breakfast at the Philadelphia restaurant Parc and walked around Rittenhouse Square Monday morning at the same time the “Reacher” cast was filming a scene nearby. After Ritchson filmed a scene walking down the street, black SUVs pulled up and the Bidens got out.

“Out walked these men, that I thought they were actors, but then the entire cast and crew started clapping and cheering. Then someone said, ‘We love you, Joe, we love you!’” an eyewitness told CBS. “I thought it was the end of the scene — that they were wrapping for the day. And no, it was, you know, Joe Biden decided he needed some breakfast at Parc Rittenhouse.”

The Bidens’ surprise appearance caught the cast, crew and onlookers by total surprise. Joe and Hunter Biden spent an hour inside the restaurant chatting with the “Reacher” crew and took photos with fans.

There’s currently no release date for “Reacher” Season 4 on Prime Video, but production began earlier this month. Joe Biden’s public appearance also comes a month after he revealed that he had been diagnosed with prostate cancer.