Not that there's much to spoil. People try to kill John Wick. John Wick kills them. Other people kill and are killed in the periphery. We get to see increasingly implausible bits of the assassination para-society that apparently exploits about 10% of the workforce. Horse-fu and dog-fu turn out to have been previously underestimated combat styles.
It's not John Wick, but it's a bit better than John Wick 2, without being in any way different from them.
Two minor observations:
- Parts of the fights turn out to be funny just out of sheer bloody-mindedness, although there's only a couple of bits I'd call gory. People are fighting for their lives, and you can see it in how they just go for it without, save some exception, grandstanding or looking for style points.
- Seeing John fight in the background while the camera looks at somebody else is both funny and awesome.