This episode, once again, starts off with a flashback to a young Walter, who was one sassy child, but thankfully his sister Megan has his back. Currently, Megan is suffering from MS. What's interesting is that Walter has only mentioned her twice before.

Walter isn't the only one thinking about the past. Agent Gallo opens up about his kid. Happy remembers her father. Toby is fixiated on his ex-fiancé.

Scorpion gets called to the Governor's mansion, where the CDC is set up, and the Governor's daughter Helena is in a hospital bed. It turns out, someone programmed a computer virus to only attack Helena's computer, and a biological virus to only infect Helena.

After locating the hacker who sent the viral email, the team learns that Helena is not the only girl who is sick. There are three other children who are suffering from the virus. Guess what all four families have in common? A pharmaceutical company, specifically a drug trial. This specific drug was remarketed to help asthma, even though it greatly helped sufferers of another disease.

When the law gets in the way, Walter decides that they are going to break in to get what they need. This isn't the first questionable thing that Walter has done today. He has attacked poor, unsuspecting mugs. Paige voices her concerns to Agent Gallo. 

Just when things are looking up, the team learns that there is a fifth target - the Governor. He isn't just going to get sick. He is going to die immediately after being infected with the virus. Thankfully, the team gets there just in time to capture the bad guy, and set off the fire alarms, thus killing the virus.