Last week, Science reflected on major achievements in science in 2023, from weight loss drugs and a malaria vaccine to exascale computing and advances in artificial intelligence. These are all impressive developments and provide yet more testimony to the power of science to continually expand the quality of our lives while deepening our understanding of the world. Even so, it's hard to end the year without some worries about 2024. Wars in Ukraine and Gaza will grind on in the new year, and the United States is headed toward perhaps the most consequential and divisive presidential election in more than 160 years. These events-and similar ones around the world-will challenge the cohesiveness and determination of the scientific community as never before.