The hunt for Rebecca Lowe is on! With a citywide search in progress, Neal and Peter try to get inside her mind, but Rebecca herself soon makes the extent of her plan clear. It turns out the murderous mastermind has injected Mozzie with a slow-acting poison. Bring her the diamond, and the antidote is theirs. Fail, and their friend dies a protracted and painful death.
With no time to lose, Neal, Peter and Mozzie follow the symbols in the Moscone Codex to a stone fort in Queens with ties to the Freemasons. His life on the line, Mozzie quickly put them on the path laid out by Moscone, but as frustration sets in and the poison begins to take effect, Mozzie is overcome.
Now, with their friend's condition deteriorating in the hospital, and Jones and Diana tracing Rebecca's steps in search of an antidote, Neal and Peter must follow the clues left by an enigmatic painter more than a century ago. But will they find the diamond before it's too late? And even if they do, can they really trust Rebecca to hold up her end of the bargain? Neal is confident that Rebecca's feelings for him will protect not only himself, but also those closest to him. But Neal above all should know not to make a true criminal choose between love and freedom...