. >> announcer: "pbs newshour weekend" is made possible by judy and josh westin, joy b. hale, the wallet family, in memory of miriam and ira d. wallet, bernard and irene schwartz. corporate funding is provided by mutual of america, designing customized, individual, and group retirement products. that's why we're your retirement company. additional support is provided by -- and by the corporation for public broadcasting and by contributions to your pbs station from viewers like you. thank you. narrator: althorp house. family home of the late diana, princess of wales. an english manor house where kings and queens are frequent visitors. as once were the ancestors of us founding father and first president, george washington. george washington's family, before they left england, were connected with mine. the washingtons were frequent visitors here. socially, they were great friends of my family. narrator: for the first time, this most elegant of england's homes throws open its doors... allowing us to share the upstairs and the downstairs. secrets of althorp, the spencers.

by looking at bill o'reiley's book, killing lincoln, b and not only that, take the so-called costars, the major names around them, washington, haleaunting. >> now we need to know who these six are. >> they are the every day man and the every day woman. you have a woman who is a socialite. we know her at agent 365. we'll have a definite idea of who the identity is. people are helping me around the country right now. i'm getting e-mails from everywhere from rhode island to northern california with different theories on it. >> to crack the code. and for those of us audience who aren't familiar with what the code even is, what's the mystery point? >> great point. what happens is there is so much nervousness among the spies of not being caught, nathan gets hanged in two days. they know if they're caught, their families are wiped out by the british and they are killed on the spot. so washington, feeling responsibility, says, okay, i have this john jay guy to give us some invisible i happ visibv. you would have a number, you wouldn't have a name. so, for example, washington was 711. abraham the farmer was 712. robert townsend the dry go