Cousins Patrick and Beth work to protect runaway slave Sally as they travel by train with President-elect Abraham Lincoln through northern New York state in 1861 aboard The Lincoln Special, getting assistance from Mrs. Mary Todd Lincoln and her son Willie along the way.

"Patrick and Beth knew they'd be facing a danger more fierce than a polar bear or a walrus, but they never thought their opponent wouldn't be large enough to see. After arriving in Alaska in the winter of 1925, they discover that a very small enemy--a disease called diphtheria--is sweeping through the town of Nome. Can Patrick help retrieve enough medicine for the children by riding along with Clearsky and his team of sled dogs? Meanwhile, Beth makes...