Vandalism at the manor forces Maren to confront local resistance to the investigation. She discovers a mysterious sealed wall in the east wing that suggests hidden secrets. With Jonah's support, she determines to uncover what lies behind it.
Eleanor arrives with controlling buyout plan, gets called out. Defamation lawsuit triggers community collapse - fishermen threatened, pledges withdrawn.
David asks Sloane to dinner - he apologizes properly, admits he hoped she'd come back but realizes neither of them really loved each other. He offers genuine closure before flying back to London. Sloane finds Caleb at the dock, tells him she's not going back to Boston.
Thea systematically investigates Warren Polk and traces Annie Wren's diary through probate records to Caleb Cole's barn. Discovers Margaret Wren's letter begging police to find the diary. With Caleb, finds the diary documenting Annie's observations of Judge Cairn at the courthouse.
Nathaniel Cairn launches a legal counterattack: a $50 million SLAPP lawsuit against all three sisters for defamation, plus an attempt to shut down Thea's podcast through a cease and desist to her hosting service.
Emergency meeting at Cairnwood Manor. Thea presents evidence including dead-end leads. Caleb reveals Ridgeline payment trail connecting Hammond to Cairn Trust through shell entity. Sloane admits missing Hammond connection during civil trial. Sisters unite to investigate Hammond.
Caleb meets with Sloane to discuss the settlement offer. She reveals the Cairns threatened David's career too. They share a charged moment where Sloane admits Caleb sees her differently than anyone else has. He tells her she's brave and someone who matters.
Maren and Jonah return to the manor for restoration work and conversation. They share personal details: Maren's failed engagement and search for meaning, Jonah's salvage work and lifelong obsession.
The sisters drive to Portland for a Maine Public Broadcasting interview. Thea presents documented evidence of Grandmother Edith's assault and the Cairn cover-up. Sloane exposes the Whitfield/Granite Coast connection. Maren speaks emotionally about giving Edith her voice.
Caleb comes to Sloane's apartment. She apologizes - should have trusted him, fell into old control patterns. He's still angry but understands his grandparents' choices now. They agree the Cairns sent the letter to break them apart - don't want to give them what they want.
Thea arrives unexpectedly at Cairnwood. Sisters examine the basement false wall together, discovering a mason's mark in the mortar. Warren Polk interrupts, realizes they've found the mortar evidence, and makes an urgent phone call. Thea assesses Jonah and begins to trust Maren's judgment about him.
At the lighthouse keeper's cottage, Maren discovers that while Davis's people emptied the main safe, they missed a hidden space behind a collapsed wall.
