Try to scare them off.

Thinking fast, you reason that you are pretty confident that the group had no firearms. That puts you at a big advantage for as long as you can keep them at arms' length. Perhaps you can even deter them entirely. Even better is if they barely see you at all, and have no idea just how outnumbered they have you.

You raise the shotgun, sighting quickly towards the movement of the person crossing the street towards you. Aiming a little way ahead of them, not yet wanting to injure, you fire just as they approach a decrepit-looking fire hydrant.

The bang is extremely loud, a sudden and immense contrast to the silence of the town around you. It's the first time that you've fired this gun, and without a stock it bucks wildly in your hands. You can see that the shot hit the hydrant and has sent the scavenger running for the nearest cover they can reach. Working the pump action, and steadying your nerve, you then point the weapon towards the corner where you sighted the other person. You think you see a flash of movement, and you fire again.

This time you're much more prepared for the noise and the recoil. The gun still jerks in your hands, but you're able to soften your wrists and let it do so without affecting your balance like it did the first time. Your target was much further away, and the scattering shot raises a cloud of brick dust from a fairly large area of the wall.

Remembering how you loaded the three shells, you know that the final shell you have in the magazine is a much more lethal heavy shot cartridge that will most likely fatally wound anybody it hits. The two shots fired so far would probably bring someone down as well, and given the paucity of medical care available likely would kill them before too long, but the final shot is designed to cleanly kill a deer, and will have a devastating effect on a human.

Reasoning that the people ahead of you haven't yet given you a reason to kill them, and hoping that they feel outgunned already, you turn around, gesturing to Todd to get moving, and start to hurry along behind him down the alleyway.

It seems quiet behind you, and you dare to hope that they've got the message and are backing off. As you come to the opposite side of the block, you look in all directions before starting to sweep back around in the direction of home.