World, meet Omicron; Omicron, meet a lot of people who are very, very anxious to know more about you. The arrival of the newest coronavirus variant, first identified in Botswana and South Africa and now present in the United States, might be bad news, or it might be terrible news—or maybe it’s just a temporary distraction from Delta. Ultimately, Omicron’s effect on the course of the pandemic will be determined by three factors: its transmissibility; the degree to which it evades our existing immune defenses; and its virulence, or the severity of the disease that it causes. If Omicron turns out to jump between hosts with ease, blow past our neutralizing antibodies, and cause unusually dangerous complications, we’ll all be in deep trouble. But it could also turn out to do a lot of other things, with more subtle implications. If Omicron ends up being super contagious, for example, but mild in its symptoms, that might even be a good thing—a perfect variant, just in time for Christmas.