WARNING: The following contains spoilers for Cells at Work! Season 2, Episode 6, "Harmful Bacteria," now streaming on Funimation.
In Cells at Work!'s sixth episode of Season 2, an old enemy returns with a vengeance, adding more trouble for White Blood Cell, Killer/Memory T and NK Cells' plates. Cancer Cell was one of the more complex characters in the first season, and his death left many viewers torn about how they felt. Although it looks like U-1146 is unemotional and unfeeling, Cancer Cell's death left a stronger impact on him than he thought.
The First Encounter with Cancer Cell in Season 2
The heroes arrive at the large intestine where they meet AE3803, but toxic fumes exude out due to the imbalance of bacteria in the large intestine. U-1146's mind is elsewhere, thinking about the whereabouts of Cancer Cell. Meanwhile, Killer T Cell has switched hats to become a Memory T Cell, so he can use his past experience of facing off against Cancer Cell to help when he eventually confronts him. Before he does that, he has to deal with his rival NK Cell who always riles him up. U-1146 leads Ordinary Cell up to a certain point in the intestine before they part ways.
As the three of them search for Cancer Cell, a sound alerts NK Cell and puts the rest of them on guard: Cancer Cell is heading their way. Multiple hands shoot from the ground up, restraining Memory T and U-1146 and almost catching NK Cell before she breaks free and kills Cancer Cell...
... Or so they thought. The Cancer Cell that they just fought was only a copy of the real one, who is still hidden somewhere in the body. The floor underneath them collapses, pulling them all down where Cancer Cell awaits. Cancer Cell mocks them, asking them if they'll be on the side of justice once again or if things will be different. The three of them launch into battle, but Cancer Cell catches and attacks them easily.
A Breach in the Large Intestine
Meanwhile, a school field trip isn't without incident. The platelets are there to visit the large intestine, which looks like an aquarium, to visit an exhibit about good bacteria. After AE3803 makes her delivery, she visits the platelets. While they're there, trouble comes in the form of harmful bacteria invading the large intestine.
The mucous barriers aren't strong enough to hold the trillions of bacteria back. Soon enough, the barrier bursts and the bacteria break through. Ordinary Cell has no choice but to run for his life, with the lactic acid bacterium in his arms. In the aquarium, AE3803 has to figure out a way to protect the platelets from the toxic fumes and the incoming bacteria, after the tour guide jumps ship.
White Blood Cell's Role
Ordinary Cell questioned why U-1146 chose to protect him and the lactic acid bacterium when he previously had no qualms in killing every bacteria and infected cell in sight. U-1146 admits that part of his job is to kill, but that's not his real purpose. His job is to protect the body, which means he'll try his best to save the good cells when possible.
The juxtaposition of Ordinary Cell and Cancer Cell over the past few episodes of Cells at Work! might speak to a life that Cancer Cell could have had if it hadn't been for cell division gone wrong. After all, Cancer Cell was once an Ordinary Cell. This parallel is also a reminder that Ordinary Cell could have ended up as a Cancer Cell too, and could have been standing opposite of U-1146 rather than beside. It was only by a stroke of luck that these two cells' fates were reversed.
All three immune cells are occupied with fighting Cancer Cell, leaving the front line of defense weaker than normal. With the large intestine being invaded by bacteria, putting AE3803 and the Platelets in danger, it will be interesting to see who will be the heroes of these two battles. Could it be the mysterious figure in high heels who shows up at the end of the episode?