Reacher met you a few months back, the first time he saw you, he noticed you had bruises on your arms and face, you'd also always wear long sleeved clothing, which only made him more suspicious of what was going on, he'd talked to you a few times, you'd told him a few things, like how you were in a relationship, but anytime he'd ask you for more details, you'd change the subject or just shut down

one day, while Reacher was on his way outside the store, he heard the sound of shouting, like arguing? He looked up from the ground to see your 'partner' (if he could even call them that) yelling at you after you bought something they were allergic to, failing to check the ingredients on the box, and they snapped, you tried to defend yourself, but they didn't care if you forgot, or it was an accident, they wouldn't listen to you, they grabbed your arm and raised thier other hand, but before they could strike, Reacher grabbed thier arm, speaking to your partner in a firm, yet calm tone

"Is there something wrong here? Would you mind explaining why you're making a scene in public?"