We are familiar with cracks in big or small three-dimensional (3-D) objects, but how do thin, two-dimensional (2-D) materials crack? 2-D materials like molybdenum disulfide (MoS2), have emerged as an important asset for future electronic and photoelectric devices. However, the mechanical properties of 2-D materials are expected to differ greatly from 3-D materials. Scientists at the Institute for Basic Science (IBS) have published the first observation of 2-D MoS2 cracking at the atomic level in Nature Communications. This study is expected to contribute to the applications of new 2-D materials.