Plot summary
After both of their personal and romantic issues fail with Paige and Happy, Walter, Toby, and the rest of Scorpion put their plans on pause as they work with the U.S. Navy to stop two out of control fighter jets taken over by hackers while flying over Los Angeles, targeting their weapons at each other. The hackers also cyberjack four U.S. destroyers and position the ships 300 yards (274 m) outside Miami, Boston, Portland, and Long Beach with high explosive BGM missiles pointed at the cities. This forces the U.S. military to ground all planes and shut down the nuclear missile silos, leaving the country defenseless.
The hackers are back-traced to Bulgaria. Happy and Toby successfully help the Navy regain control of the remaining fighter plane after the hackers use it to shoot down the other. However, Walter and Paige are unsuccessful at hacking the hackers' signal and are almost killed trying. Meanwhile Sly, Cabe, and Tim travel to Sofia, Bulgaria in a Valkyrie to find the hackers, where Sly shows off his card counting skills to get the attention of a crime boss they need to find the hackers.
Credits
Adapted from Wikipedia contributors, List of Scorpion episodes. HTML formatting and reference markers removed.