Caitlin and Caleb as they find themselves, once again, back in time -- this time, in the London of 1599. London in 1599 is a wild place, filled with paradoxes: while on the one hand it is an incredibly enlightened, sophisticated time, breeding playwrights like Shakespeare, on the other, it is also barbaric and cruel, with daily public executions, torture, and heads of prisoners impaled on spikes. It is also a time of superstition and grave public danger, with a lack of sanitation, and the Bubonic Plague spreading in the streets, carried by rats. In this environment Caitlin and Caleb land, on the search for her father, for the third key, for the mythical shield that can save humankind. Their mission takes them through a whirlwind of London's most amazing medieval architecture, through the British countryside's most breathtaking castles. It takes them back into the heart of London, where they just might meet Shakespeare himself, and see one of his plays live. It brings them to a little girl, Scarlet, who just might become their daughter. And all the while, Caitlin's love for Caleb deepens, as finally they are together -- and as Caleb might just finally find the perfect time, and place, to propose to her. Sam and Polly have traveled back, too, and as they find themselves stuck together on their own journey, their relationship deepens, as they each, despite themselves, can't help feeling more deeply for each other. But all is not well. Kyle has come back, too, as has his evil sidekick, Sergei, and they are both intent on destroying everything good in Caitlin's life. It will be a race to the finish, as Caitlin is forced to make some of the hardest decisions of her life if she is to save everyone who is dear to her, save her relationship with Caleb -- and try to make it out alive.