If you mean chapter 14, post Edge Knot City

When you’re taking Lou to the incinerator

You’re right at the end, there’s no more bosses. It’s just a bit of hiking and then a bunch of cutscenes. Then you’re in the epilogue and time rewinds so you can keep playing. Might be a bit of a weird place to start playing again though, as you just boot up the game after so many years just to watch a cutscene or two and then credits roll lol.

If you mean chapter 6, before reaching Edge Knot City

When Deadman takes the baby to recalibrate it

As you can probably guess by the chapter numbers, you are nowhere near the end of the game, sorry. There IS a bossfight, but you only have to do the first section alone, then you reunite and do the actual main fight together.