I have traditionally not enjoyed time travel books very much. The attendent temporal complications tend to give me headaches.
However, I am somehow in the midst of my third time travel book in a row - and I have enjoyed all three - in very different ways, as the three have been very different!
Connie Willis's The Doomsday Book was a serious novel filled with sympathetic characters facing terrible things - for the most part with great courage and compassion and dignity.
Virginia Baker's Jack Knife was an action filled adventure story involving Jack the Ripper!
And now - John Varley's Mammoth is, so far, just plain fun.
A multibillionaire has hobbies.
He decides that, for his latest project, he wants to clone a mammoth.
This guy never does things halfway or halfassed, so he sends a bunch of teams out to the Canadian Arctic to find the best preserved mammoth corpse possible, as a DNA donor (they find frozen ice age animal carcasses up in the Arctic sometimes).
So one of his teams finds the best preserved mammoth body ever - but there is a pretty big complication...nestled up beside the mammoth and frozen right with it is a pair of human corpses, dressed in furs. But one of them is wearing a wrist watch. And they have a brief case with them...
The billionaire has found his mammoth all right - and he has found a whole lot more in the bargain!
