Murder, Inc. was a group of people who did really bad things. They would hurt and kill people for money. It's like if someone paid you to really hurt or even kill someone else, but way worse. The people in Murder, Inc. were really good at keeping their secrets and not getting caught for a long time. But eventually, the police found out what they were doing and made them stop. So, it's very important to always do the right thing and be kind to others because hurting or killing someone is never okay.