Erwin needs to pull an all nighter to catch up on paperwork since he has been busy, and Hange says she needs to do the same. She asks if she can work next to Erwin and he lets her. Hange says monotonous work is more fun with a friend and talking while she works gets her going. She notes she is getting a lot of work done and calls it the Erwin Effect, but Erwin thinks about how his work has not progressed at all due to the Hange Effect.
As they continue to work, Erwin mutters to himself about an application and Hange asks him to keep it down because she is working. Erwin does not miss the irony. She also notices his great posture as he works. Deciding to take a break, Hange tells him to relax while she makes them coffee. Erwin suddenly deflates after she leaves and instantly sits up straight again when she unexpectedly returns early to ask him whether he wants milk or sugar.
Hange falls asleep while working and Erwin greets her good morning when she wakes. She looks for her pen, but cannot find it and Erwin comments on her fancy hairpin, which turns out to be her pen. Hange asks Erwin what he is doing playing pranks while Erwin stifles a laugh.
She asks Erwin if he peeked at her research and he did not. Hange reveals that she is researching people she knows and the other day she was studying Mike. She asks Erwin if he can guess who she is researching now and he asks with shock if she is researching him.
Finally, Hange declares that she is finished and she will leave Erwin alone so he can get some work done. Erwin face-plants on his desk and goes to sleep.
The next morning Hange and Levi wake him up and Erwin panics over having fallen asleep with so much work to do. He fails to notice that his signature has rubbed off on his forehead. Levi mentions this to Hange, but she says it will be funnier not to tell him.