The professor had been clear.

“If your group can’t finish the prototype by Friday, you all fail the unit.”

My group was supposed to be four people. Two had already ghosted. That left me with the two senior students who actually showed up: Roman Hale and Julian Voss. Both were a year older, both were used to getting their way in the department, and both had looked at me longer than necessary when the professor assigned us together.

We took over the empty engineering lab on the third floor after the building closed. The doors locked automatically at nine. Roman had a faculty key from his research assistant job. By...