Guardian Recap: Episode 25 "The Case of the Infectious Personalities"
When he touches Zhu Hao, Xiao Guo doesn't seem to notice the bit of dark energy that invades his body and neither does the Chief. Since they have no leads at the moment, they decide to send the cabbie to Haixing headquarters and rejoin the rest of the crew in the bullpen. Da Qing and Lao Chu have interviewed the witnesses to the altercation that got the cabbie in trouble and found no one who could help justify the man's irrational anger. The attack was unprovoked.
Xiao Guo joins the group sitting around the table and an innocent attempt by Zhu Hong to read his daily journal leads to a very out of character burst of anger toward both her and Lao Chu. Stunned, everyone watches him leave without saying a word. (That dark energy he absorbed is already having an effect.)
The next day, Professor Shen greets his class at the University and finds Zhu Hong sitting in the back of the room. (Pfft. Notice how his entire class is female.) She gives him an odd excuse of wanting to close the gap between her and the Chief, and Shen Wei moves on to start his lecture.
Sometime later, the crew gathers to discuss how there is now a teenager who has been diagnosed with the same condition as the cabbie and wonder if there is a connection. Shen Wei starts to tell Yunlan about how Zhu Hong had been in one of his classes when she suddenly appears all glammed up like she's going on a date. She approaches him in a shy, almost coy manner and even calls him by his given name (Oh boy. Her too?) When he tries to avoid her, she gets flustered and runs away.