Alma Ch25

It may seem to be getting worse and worse because the Lamanites become more aggressive, but good news is that the wicked priests of Noah finally get whats coming to them! Then even better, more Lamanites are converted to join the Anti-Nephi-Lehies and start to keep the law of Moses.
The Lamanites that did not give up their weapons and convert to the Lord in the last chapter become more angry but direct it at the Nephites for apparently causing them to attack and kill their brothern (v1). The armies start to attack Nephites and these are the armies that attacked Ammonihah and brought to pass the judgment of God upon them, then if you remember, were driven back by Nephite armies (v2-3). Those people that were slain were mostly the Amulonites who are the decendents of the priests of Noah who had been promised that they would suffer as Abinadi had, and guess what, it happens (v4-9).
I'm gonna be a little more specific on how it all came about though. So the people who survived against the Nephites ran away into the wilderness and started to believe the words of Aaron. The seed of Amulon still didn't believe and they were sort of in power and decided to put to death all those who started to believe, but being the majority, they were hunted down and slain (v7-9). Abinadi had said, "What ye shall do unto me shall be a type of things to come," which means that those who sentenced him to burn were burned (like Noah and a few other of the seed) or hunted down (like the rest (v10-12).
The Lamanites returned home from fighting the Nephites and joined the people of God by burying their weapons, living righteously by keeping the commandments, and following the law of Moses (v13-15). They knew the truths of the law of Moses too. The truth that this is a law that was not fulfilled at that time but it was there to strengthen their faith in Christ until He comes to bring salvation (v16). The sons of Mosiah, and company, went through quiet a bit of trial, but they were faithful and now witness the great fruits of their labor in the whole, like, around 30ish years they are out there (v17).