Grandpa?
Edward M. Lerner
In Ethiopia With a Mule
Dervla Murphy
Discworld 41: The Shepherd's Crown
Terry Pratchett
Discworld (41)
026 The Phantom Freighter
Franklin W. Dixon
The Hardy Boys Mystery Stories (26)
Sir Gawain and the Green Knight/Pearl/Sir Orfeo
J. R. R. Tolkien