Another new character that was introduced in a previous book, the Night Mare is the heroine of this book. The barbarians (us non magic folks) are again invading Xanth and the Night Mare must carry a warning to the King. A bit (tiny bit) more serious than some of the others. ( )

About Xanth
Night Mare is the sixth book of the Xanth series. These books are intended as humorous fantasy, you can expect happy endings and, as a character in a later book points out, nothing really bad ever happens to a major character. They are set at a time corresponding to ours in the magical and pun-infested land of Xanth: every human born in Xanth has a magic talent of some kind. It occupies the same position as the state of Florida, but the border is normally impervious from the non-magical side, which is referred to as Mundania and its inhabitants as Mundanes. As well as from modern Alabama and Georgia, Mundanes can sometimes enter Xanth from other times and places. This has permitted various waves of peaceful or warlike incursion into Xanth.

About this book
The background of Night Mare is a purely violent incursion of Carthaginians who were expecting to reach northern Italy. The main story line is about how the Xanthians overcome the invasion with the help of the titular character, Mare (pun!) Imbrium, Imbri for short, but the book continues the stories and develops the characters of people from previous books and new complexities of Xanth appear.

In the previous volume, Ogre, Ogre, Imbri acquired half(!) a soul. Anthony's souls are magical entities whose properties and purpose tend to vary from story to story, depending on what the plot needs: in this book, the effect of the half soul on the normally soulless night mare is to diminish her previous delight in inflicting unpleasant dreams on sleepers. As a result, she is no longer carrying out her job effectively and the Night Stallion sacks her from dream duty. Instead, he assigns her as liaison between the dream world and the King of Xanth during the emergency, and to facilitate this she will be solid in bright light but insubstantial in the dark. Her immediate task is to take the message "Beware the Horseman" to Chameleon (see first book), who will pass it on to King Trent. Being unused to solidity, she bumps her head and forgets her mission. She meets a white stallion, which is surprising because there are normally no simple horses in Xanth, and befriends it, then meets the evil Horseman himself, a highly skilled rider who is one of the leaders of the Mundanes. When he refers to himself as Horseman, she remembers her mission. She has repeated encounters with both of them throughout the book: the stallion makes itself useful to the Xanthians by carrying people around, and the Horseman keeps popping up unexpectedly.

No Xanth book would be complete without someone overcoming three challenges to enter Humphrey's castle and consult him for advice, which Imbri and Chameleon do when they get together, but he merely adds "Break the chain" to the message "Beware the Horseman".

When they get back to King Trent, they find that he is alive, but completely mindless. There is a designated successor, Dor (hero of the third and fourth books), but after some initial successes, he too becomes mindless. By law and tradition, Xanth must be ruled by a King who must be a Magician, that is, have an exceptionally powerful magic talent, but Magicians are in short supply. As each makes some progress against the invasion before being incapacitated, it becomes necessary to reinterpret the rules more liberally so that more kings are available.

Imbri solves the problem of what has happened to the kings' minds and it is established the the Horseman is operating a magical device to cause the effect. Eventually the Horseman is killed in a confrontation between him, the stallion and Imbri. It is then necessary to release the kings, which Imbri accomplishes by an act of self-sacrificing heroism.

Conclusion
In my opinion Night Mare is weaker than the earlier books, but if you liked them, you will probably like Night Mare too. If you are new to the Xanth series, Night Mare is not the place you want to start (and if you dislike puns, don't start at all). Instead, try the first book, A Spell for Chameleon, or the third, Castle Roogna.

(Thanks to members of Reviews reviewed for suggesting improvements.)

You have got to love the tag-line for the book "Night Mare!" "The danger to Xanth was so great that only a night mare could offer hope!" Night Mare's in a Xanth are a little different than what we are used to here in our Mundane existence. In Xanth, things tend to be more literal, and Night Mare's are actual Mare's who's job it is to deliver the bad dreams to the citizens of Xanth.

One Night Mare, Mare Imbrium, has been given a special mission. Normally the Night Mare's can't go out during the day, but because she has half a soul (see the book "Ogre, Ogre) the Night Stallion is able to give her special dispensation. Now she has a special message for the King of Xanth, and she is destined to become a liaison between him and the Night Stallion.

The people and government of Xanth undergo a lot of changes in this book, but they are for the better! I really enjoyed reading it and I look forward to seeing where Piers Anthony takes us next. ( )

See A Spell for Chameleon. ( )