Beakman explains what the heart is and how it works using a model and an animated clip. He shows how it contracts to move blood around and that the blood carries nutrients and oxygen to all of your cells.
Tuck travels quickly through the bloodstream because Jack's heart rate has increased from being pursued by some villains. Tuck tries to stop his vehicle and avoid entering the heart through the tricuspid valve, which could be fatal to Jack.
Neil and Shaun use augmented reality (AR) to practice a cardiac surgery on a patient's heart and find a scenario in which he would survive. They find a solution with an exceedingly low margin of error.