As Megan's condition worsens, the team gathers at the hospital. As they arrive, they find a pathogen has infected the hospital threatening all of their lives.
Team Scorpion is torn apart and uncertain about their future as a unit, but they are forced to come together to save Walter's life when his car teeters on the side of a cliff.
Team Scorpion must save a young girl with no immune system who is also a new friend with of Happy's after a storm. Paige and Cabe has to cut people out of their lives.
Walter learns Cabe's long-hidden secret regarding the Baghdad mission and it threatens to tear Team Scorpion apart. Meanwhile, Ralph puts his life in danger to help the team.
Walter's attempt to "normalize" goes horribly wrong when a nefarious virus is uploaded to his computer, turning Scorpion's new "smart" building project into a burning death trap with people locked inside.
Team Scorpion is blackmailed to break into the United Nations to assist in the assassination of a menacing arms dealer. Also, Sylvester makes a bold move to protect Megan's wishes.
A 10-year-old boy is trapped in a rockslide/sinkhole near the beach. The team must find a way to rescue him before the rising tide fills it up with water.