My ex-boyfriend is insisting he was abducted into an underground fight club—how should I deal with my skepticism?

My ex-boyfriend (25M) once shared a harrowing experience from his teenage years when he was kidnapped by gang members and coerced into fighting in an underground ring. He described how some kids participated willingly, but others, like him, were threatened and had no choice but to fight. He recounted eerie scenes involving masked bettors, weapons, and how they were even forced to take MDMA to dull the pain. He once took me to a location he claimed was where the fights occurred, but I could only see the top of the building, not the underground area. He appeared visibly anxious, and during a conversation about a "final fight" that he had to win to escape, he became overwhelmed with emotion and broke down in tears. A few months later, he showed me an email from someone who allegedly organized the fights, stating, "We want you back." I've been wrestling with this in my mind—could events like this really take place? If so, how frequently does it happen? And if not, what could have motivated him to share such a story? This has been heavy on my mind, and I'm struggling to process it. Any insights would be greatly appreciated, as I've felt awful for him, but since our breakup, the whole narrative seems inconsistent.