Simon and Jasmine Dale take on the challenging task of building a 21st-century, low-impact three-bedroom family home with a budget of only £500. As part of a pioneering, government-backed, sustainable village called Lammas, the couple must adhere to their fierce planning conditions of self-sufficiency or risk losing everything.
Oliver and Lyla team up on a secret mission for Diggle. Felicity finds out and disapproves of the plan and opts to stay behind. When Tobias Church launches a deadly assault against the city, Felicity must decide if she wants to send the recruits out sans the Green Arrow.