Jagger tortures the woman in white and addresses her as Antoinette, holding her underwater as he demands she give him Blackbeard's location. Her wild eyes and pale complexion suggest a strange kind of mania... yet she refrains from speaking a word.
Back on Santa Campana, Fletch leads Lowe to a hidden cave where they discover a frightening sight - barrels upon barrels of gunpowder. Clearly this stash plays into Blackbeard's secretive plot, and Lowe concludes the commodore must intend to attack Jamaica. Since Lowe's allegiance still lies with the English, he vows to finagle his way back to Jamaica and alert his spymaster.
To achieve this, he convinces Blackbeard that he knows a possible cure to his unending headaches and visions - a form of brain surgery involving a seldom-used tool called the trephine. Lowe assures the commodore that he can procure a trephine in Jamaica, and after some deliberation, Blackbeard allows him to go, with one caveat - if Lowe decides to betray him, Kate will suffer the consequences.
The warning weighs heavy on Lowe's mind when Kate confronts him about the sudden excursion to Jamaica. She questions his loyalty, and he assures her that she remains reason enough to stay faithful to the people of Santa Campana. His apparent honesty reinvigorates their romance, and they share a moment of passion before he leaves.
In a rare moment alone, Selima and Rider speculate that Blackbeard knows about their affair. Despite this, the commodore comes clean to Selima about the possibility of his condition leading to death and that she should prepare to takeover Santa Campana's leadership role. When that day comes, she must eschew her debilitating agoraphobia. Blackbeard's urging motivates Selima to force herself outside, and she walks the grounds, albeit gingerly, to the shock of everyone on the island.
Later, Balfour (now on crutches, his health a vast improvement) rekindles his own passion for Kate, and for the first time in ages, he and his wife make love. Afterwards he admits to breaking their vows - by placing his own vanity above her well-being.
Kate's not the only one wracked with guilt on Santa Campana - Nenna digs up her treasure and, as discussed, offers it to Rose in exchange for her silence. But Rose continues to press, leveraging both Nenna's attraction to her and her belief that more treasure remains for the taking. Nenna avoids this confrontation when Blackbeard singles her out to accompany Lowe to Jamaica, and when they arrive, she conducts her own secret business with a local - the purchase of a plantation all her own.
With her occupied, Lowe visits Jagger, his spymaster, and reveals Blackbeard as his captor. Yet, as their discussion escalates, Lowe finds himself defending Blackbeard and recognizing the hypocrisies of the British King (and, by proxy, Jagger). Jagger rails against Lowe's apparent loyalty to Santa Campana and its inhabitants, furious at the very suggestion and implies British forces will massacre every last one of them. Lowe presses for a compromise, and before indicating the location of Santa Campana on a map, he gets Jagger to promise he'll spare the lives of Kate and Fletch...
Except Jagger catches Lowe in a lie - the island he pointed to is known, and Jagger once visited it. Now enemies, the two fight in the office, and Jagger stabs Lowe in the side before Lowe knocks him unconscious. Lowe limps away, barely managing to hide his wound as he sneaks to a vendor and obtains a trephine. Redcoats spot him moments later, and he dodges bullets in a race that halts at the steep cliffs of the island. With no other choice, Lowe leaps into the ocean and escapes, his ship a short swim away.
That night, Blackbeard toils during his sleep due to another nightmare - yet this one trumps all the others. Not only does the same specter appear - a pale woman in white, an even more ghastly version of Antoinette - but she carries a baby in her arms. The shock startles Blackbeard awake and he sits up - afraid, unsettled and, just perhaps, going mad.