The paper investigates the non-perturbative dynamics of single-field inflation with a departure from slow-roll, using simulations to explore the impact of small-scale features in the potential on the evolution of the Universe. The authors find that oscillatory features in the potential can significantly alter the course of inflation, leading to either a forever inflating de Sitter state or regions trapped in a false vacuum. These trapped regions can form primordial black holes (PBHs) and contribute to the gravitational wave background (GWB). The study highlights the "inflationary butterfly effect," where small-scale phenomena can have profound consequences on the entire Universe. The findings have implications for both the understanding of inflationary dynamics and the detection of GWs, particularly for upcoming observatories like LISA and advanced LIGO. The work also provides insights into the small-scale physics of inflation, which is crucial for probing the non-Gaussianities and GWB in the early Universe.The paper investigates the non-perturbative dynamics of single-field inflation with a departure from slow-roll, using simulations to explore the impact of small-scale features in the potential on the evolution of the Universe. The authors find that oscillatory features in the potential can significantly alter the course of inflation, leading to either a forever inflating de Sitter state or regions trapped in a false vacuum. These trapped regions can form primordial black holes (PBHs) and contribute to the gravitational wave background (GWB). The study highlights the "inflationary butterfly effect," where small-scale phenomena can have profound consequences on the entire Universe. The findings have implications for both the understanding of inflationary dynamics and the detection of GWs, particularly for upcoming observatories like LISA and advanced LIGO. The work also provides insights into the small-scale physics of inflation, which is crucial for probing the non-Gaussianities and GWB in the early Universe.