On this episode of Person of Interest…

Samaritan is causing havoc with the stock market, and the POI team must attempt to prevent it from crashing.

Finch, Reese, Fusco and Root enter the building where the servers are in an attempt to hack in and stop Samaritan.

Unfortunately, Samaritan’s assets are waiting.

The Machine attempts to come up with possible simulations for the best outcome of success after the team is attacked.

In the first, Root and Finch go to the servers, where Finch is shot and killed. Reese and Fusco are captured by the agents, and Shaw is forced to kill a suicidal man with a bomb. She also fails to get the team the code.

In the second version, Reese and Fusco go to the servers, where Reese is shot and killed. Root is shot by the agents. Shaw is forced to kill the suicidal man with the bomb.

In the third version, the POI team sticks together going to each section as a team. They manage to prevent the crash, but the Machine is unable to get them out alive.

The Machine tells Root to follow instructions that follow along with the third version, but as the team is under attack after stopping the stock market crash, Shaw shows up raising their chance of survival.

As the team manages to get away, Shaw realizes a manual button needs to be pushed. She kisses Root and sacrifices herself for the team in order to push the button.

She is shot by a Samaritan agent.

Flashbacks reveal Finch teaching the Machine to play chess, and making various decisions and outcomes in the real world.