On Thursday afternoon last week at Twitter’s San Francisco offices, employees in costumes milled about at the company’s Halloween party as a magician performed tricks. Some attendees speculated that the emcee for the event, dressed in a scarecrow costume, was Elon Musk, who was then hours away from becoming Twitter’s new owner (the emcee was not Musk). According to a person who was present at the event, one Twitter employee guessed incorrectly in the magician’s three-card monte game, prompting another employee to joke: “You’re fired.”

By the end of this week, there was no humor in that joke. Starting Thursday night, Musk began instituting a brutal wave of layoffs at Twitter, which were expected to reduce the company’s headcount by around 50%. Some who were fired found themselves logged out of their computers while writing an email or sitting on a video call, and others woke up to find themselves locked out of corporate email accounts and Slack. Teams working on product and engineering for ads, public relations and data centers were hit hard. Some of those who survived the layoffs found themselves ambivalent and envious of their laid-off colleagues, who got months of severance while they were left with twice the workload.

The layoffs capped one of the most extraordinary seven days for any company. While dramatic changes often follow corporate takeovers, rarely do they occur with the ferocity of events at Twitter, where Musk immediately sacked several of the company’s most senior executives after completing his acquisition last week and ordered employees to bang out projects on what many viewed as inconceivably tight deadlines. Some workers set up sleeping bags in the office so they could pull all-nighters to hit those goals, all while the threat of imminent layoffs loomed over their heads.