Operation Warp Speed, the Trump administration’s bid to deliver a COVID-19 vaccine faster than any previous vaccine, is both turning heads and raising eyebrows with a major new investment that promises to shave weeks off its already ambitious timeline. Jon Cohen writes in Science that much of Warp Speed’s inner workings, including how it chooses vaccine candidates, takes place behind closed doors. But the compressed timeline and the scale of the investment—more than twice the size of commitments the United States made earlier to Johnson & Johnson and Moderna to develop other vaccine candidates—is leading to questions about both the candidate vaccine and the plans for its clinical trials.