Marcus counters with Basic Human Decency and a healthy amount of Bravado!
"Naw, mijo," Marcus replied, stepping over as the smaller man fell to the concrete. He lifted the machete to draw Tom's eye to it, and then deliberately sheathed it in full view. A peaceful gesture. Look how I'm putting away my weapon. Of course, he was much bigger and obviously not the one bleeding out on to the pavement, so he was still at a pretty solid advantage. He grinned brightly, teeth glinting in what little pre-dawn light there was. "I'm the best fucking thing that's happened to you today. Just so happens I'm a fucking nurse. You put that piece away, I'd be willing to help you out. Just to keep one less zombie motherfucker off the fucking streets. Es así de simple. Whatchu say? Sounds good, right?"
He wasn't really giving Tom that much time consider as he approached. The guy could panic and shoot him, but he seemed pretty coherent for all that he was clearly injured, and Marcus was willing to bet he'd be hopeful for help. The clothes around his abdomen were soaked through, and Marcus really wasn't in the mood to watch a stranger die. When he got close enough to see how much blood there was, he hissed through his teeth. "Mierda, es malísimo. Look, I'm not bullshitting you, mijo. I got a kit. You want to live, just say sí, por favor and be cool. I'll make it happen."
Well, he'd try anyway. That much blood... and he didn't know yet if the guy had been bitten or not on top of it. There was infection to be concerned about, not to mention the fact that any second something else could show up to give them both trouble... a raider, a corpse... a healthy group of either. Marcus was an optimist, though. Hell, if the guy died, it wasn't like he'd have to atone for making false promises.