On this episode of Person of Interest…

Reese heads up a number of the week, Anna, who works at a tech company.

He discovers that she found an algorithm that caused a person to kill himself.

The head of the company wanted to create a powerful advertising company and set up the algorithm, even preparing to kill Anna if she got in the way.

Reese and Fusco manage to stop them and save Anna.

Finch discovers a call for help from Claire, but he soon learns she is still working for Samaritan.

Claire tries to convince Finch to switch sides, but he refuses. As he is being taken away, Root shows up to rescue him.