After trying unsuccessfully to understand the coagulation cascade, most students simply give up and memorize the cascade. The problem with that way of ‘learning’ is that does not lead to anything that persists. Consequently, this interactive book was created to help students envision coagulation in a different way. Most importantly, the focus of this book is what is happening at the level of the vascular endothelium in critically ill patients, and how these processes are regulated. While the classical coagulation cascade is included, the more relevant part of this interactive book views hemostasis from a cell-based approach. Hopefully, this approach will improve a student’s ability to envision, understand and recall this information when necessary.