Amelia, Koracick and DeLuca perform a risky, groundbreaking procedure using ultrasound waves to remove a young patient's brain tumor. Meanwhile, Meredith and Jo work with different polymers to try to salvage their project submission; and Richard's AA sponsor is admitted to Grey Sloan with a DNR.

During presentations on Grey Sloan Surgical Innovation Prototypes Day, Arizona shares some cookies from an appreciative patient that, unbeknownst to her, contain a special ingredient. Meanwhile, Catherine reveals some shocking details to Jackson about his grandfather's past; and Jo steps in mid-operation on a major surgery after Bailey and Meredith are down for the count.