The present study investigates capture and escape dynamics associated with a planar, high–energy, retrograde periodic orbit around the Earth for applications to spacecraft trajectories. A lunar gravity assist plays the central role in both capture and escape scenarios. In the capture analysis, the trade–off among time–of–flights, launch energies, and insertion delta–v are revealed. A variety of solutions exists including fast, multi–revolutional, and Sun–perturbed transfers. The escape analysis, on the other hand, focuses on transfers with short time–of–flights. The search finds that a double lunar gravity assist, occurring after a departure delta–v on the periodic orbit, enables efficient escape from the Earth with substantial hyperbolic excess velocities. The overall result leads to a concept “Comet Interception from eArth retrOgrade orbIT viA Lunar gravIty Assist” using the retrograde periodic orbit as a staging post and enabling fast lunar encounters to travel toward the interplanetary region.