"Colin and Nevaeh find vintage letters that lead to interlocking mysteries from the 1970s and '80s, and they learn about 'women's lib,' the ERA, and other social issues from that time in history-and the way echoes from that era affect Colin and Nevaeh themselves. When Colin finds a shoebox full of letters hidden in a stranger's attic, he knows he's supposed to throw them away. That's his summer job, getting rid of junk. But Colin wants to rescue the...