Chris Fitton's father and Nan Mallory's mother recently married, but this isn't the Brady Bunch by a long way. Chris has spent his life in one boarding school after another, while Nan's grandmother raised her during her mother's long assignments overseas as a photographer. Even now, Chris and Nan are living with Chris' aunt Elizabeth; their parents just got married and promptly took off for a 6 month assignment in Mexico. Neither kid has seen them since before they announced the wedding.
For years, Chris' father has given him money to buy presents, since he's never with his son much himself to get to know what he'd like. When aunt Elizabeth drops Chris and Nan off at a movie soon after Nan's arrival, Chris opts to shop for a present instead. In a strange store he's never been to before, he finds a very old model inn, bearing the sign of a red hart (i.e., a male red deer).
Chris and Nan soon discover that the Red Hart carries some kind of magic; in their dreams, they find themselves in the real Red Hart, an English inn, in various periods of the past.
"The King's Hunters", in King James' reign, finds the two of them thwarting a Pursuivant who attempts to prove that the inn's owner is secretly a Catholic priest (a capital offense in that place and time). Catherine Aird's mystery _A Most Contagious Game_ would be a good read for anyone who's interested in how priests managed to survive and the tricks used to build hiding places for them.
In "The Gentlemen", a wounded Excise officer is being sheltered from local smugglers in the inn. This story makes a sharp, interesting contrast to Vic Crume's _Dr. Syn Alias the Scarecrow_, a terrific book that's also a movie by Disney with Patrick McGoohan (the hardest Disney classic to find on video as of this writing, may I add). The chief of the smugglers in "The Gentlemen" is as anonymous as the masked Scarecrow - 'he could be any man in the village, leaving out the parson and the squire.' (If you've read or seen the Scarecrow's story, you'll get the joke.)
In "Hue and Cry", Chris is falsely accused of setting fire to Squire Mallory's barn, a blaze that could have killed several men. Harry Hawkins, a friend of his father's days in Wellington's army, one of the Bow Street runners, is called in by Ira Fitton to uncover the truth. (This is *long* before the runners evolved into the Bow Street Station of Anne Perry's Thomas Pitt.)
In the present, the kids have their own troubles, apart from getting along with each other. Nan is 'befriended' by the most popular girl in class - only to find that the price of entry into her circle is too high. Chris, on the other hand, is the favorite target of the most popular kid in *his* school - the bully who's captain of the soccer team. The lessons they learn in the past stand them in good stead.