"Jack Strong" is a movie about a man named Ryszard Kuklinski who was a secret agent in Poland back in the 1980s. His job was to protect his country, but he became worried that his own government was doing bad things and he didn't want to be a part of it. So, he decided to become a spy for the United States to help them understand what was going on in Poland.
But being a spy was very dangerous, and if he was caught he could be killed. So, he had to be very careful and keep his spying a secret. He would sneak important papers out of his office and give them to his U.S. contacts, and sometimes he would even sneak out of the country to meet with them.
All of this was very stressful for Kuklinski, and it put his family in danger too. But he believed that it was the right thing to do, even if it meant risking his life. Eventually, the government found out what he was doing and he had to run away to the United States to avoid getting caught.
"Jack Strong" is a movie that tells the story of Kuklinski's dangerous and heroic actions, and it shows how difficult it can be to stand up for what you believe in, even when it means taking big risks.